1 kilometre
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The following are examples of
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
for different lengths. __TOC__


Overview


Detailed list

To help compare different orders of magnitude, the following list describes various lengths between 1.6 \times 10^ metres and 10^metres.


Subatomic scale


Atomic to cellular scale


Cellular to human scale


Human to astronomical scale


Astronomical scale


Less than 1 zeptometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to . To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths shorter than 10−21 m (1 zm). *1.6 × 10−5 quectometres (1.6 × 10−35 metres) – the Planck length (Measures of distance shorter than this do not make physical sense, according to current theories of
physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
.) *1 qm – 1 quectometre, the smallest named subdivision of the metre in the SI base unit of length, one nonillionth of a metre *1 rm – 1 rontometre, a subdivision of the metre in the SI base unit of length, one octillionth of a metre *10 rm – the length of one side of a square whose area is one shed, a unit of target cross section used in
nuclear physics Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the ...
*2 ym – the effective cross-section radius of 1 
MeV In physics, an electronvolt (symbol eV, also written electron-volt and electron volt) is the measure of an amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacu ...
neutrino A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...
s as measured by
Clyde Cowan Clyde Lorrain Cowan Jr (December 6, 1919 – May 24, 1974) was an American physicist, the co-discoverer of the neutrino along with Frederick Reines. The discovery was made in 1956 in the neutrino experiment. Frederick Reines received the Nobel P ...
and
Frederick Reines Frederick Reines ( ; March 16, 1918 – August 26, 1998) was an American physicist. He was awarded the 1995 Nobel Prize in Physics for his co-detection of the neutrino with Clyde Cowan in the neutrino experiment. He may be the only scientist i ...


1 zeptometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to . To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−21 m and 10−20 m (1 zm and 10 zm). *2 zm – the upper bound for the width of a
cosmic string Cosmic strings are hypothetical 1-dimensional topological defects which may have formed during a symmetry-breaking phase transition in the early universe when the topology of the vacuum manifold associated to this symmetry breaking was not simp ...
in string theory. *2 zm – radius of effective
cross section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture & engineering 3D *Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) **Abs ...
for a 20
GeV GEV may refer to: * ''G.E.V.'' (board game), a tabletop game by Steve Jackson Games * Ashe County Airport, in North Carolina, United States * Gällivare Lapland Airport, in Sweden * Generalized extreme value distribution * Gev Sella, Israeli-Sou ...
neutrino A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...
scattering off a
nucleon In physics and chemistry, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines the atom's mass number (nucleon number). Until the 1960s, nucleons were ...
*7 zm – radius of effective cross section for a
250 __NOTOC__ Year 250 (Roman numerals, CCL) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Traianus and Gratus (or, less frequently, y ...
GeV neutrino scattering off a nucleon


10 zeptometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−20 m and 10−19 m (10 zm and 100 zm).


100 zeptometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−19 m and 10−18 m (100 zm and 1 am). *177 zm –
de Broglie wavelength Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave ...
of
protons A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mas ...
at the Large Hadron Collider (7 TeV as of 2010)


1 attometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to . To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−18 m and 10−17 m (1 am and 10 am). *1 am – sensitivity of the
LIGO The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large ...
detector for gravitational waves *1 am – upper limit for the size of quarks and
electron The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no ...
s


10 attometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−17 m and 10−16 m (10 am and 100 am). *10 am – range of the weak force


100 attometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−16 m and 10−15 m (100 am and 1 fm). *100 am – all lengths shorter than this distance are not confirmed in terms of size *850 am – approximate proton radius


1 femtometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to . In
particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) an ...
, this unit is more commonly called a , also with abbreviation "fm". To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−15
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s and 10−14 metres (1 femtometre and 10 fm). *1 fm – diameter of a
neutron The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons beh ...
, approximate range-limit of the
color force Color Force is an American independent film and television production company founded in 2007 by producer and film executive Nina Jacobson after her 2006 termination as president of Disney's Buena Vista Motion Pictures Group. Its films inclu ...
carried between quarks by gluons *1.5 fm – diameter of the
scattering cross section In physics, the cross section is a measure of the probability that a specific process will take place when some kind of radiant excitation (e.g. a particle beam, sound wave, light, or an X-ray) intersects a localized phenomenon (e.g. a particle o ...
of an 11
MeV In physics, an electronvolt (symbol eV, also written electron-volt and electron volt) is the measure of an amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacu ...
proton with a target proton *1.75 fm – the effective charge diameter of a proton *2.81794 fm –
classical electron radius The classical electron radius is a combination of fundamental physical quantities that define a length scale for problems involving an electron interacting with electromagnetic radiation. It links the classical electrostatic self-interaction energ ...
*3 fm – approximate range-limit of the nuclear binding force mediated by
meson In particle physics, a meson ( or ) is a type of hadronic subatomic particle composed of an equal number of quarks and antiquarks, usually one of each, bound together by the strong interaction. Because mesons are composed of quark subparticles, ...
s *7 fm – the radius of the effective scattering cross section for a gold nucleus scattering a 6
MeV In physics, an electronvolt (symbol eV, also written electron-volt and electron volt) is the measure of an amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacu ...
alpha particle Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be pr ...
over 140 degrees


10 femtometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−14 m and 10−13 m (10 fm and 100 fm). *1.75 to 15 fm – Diameter range of the
atomic nucleus The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. After the discovery of the neutron ...


100 femtometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−13 m and 10−12 m (100 fm and 1 pm). *570 fm – typical distance from the atomic nucleus of the two innermost electrons (electrons in the ''1s'' shell) in the
uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
atom, the heaviest naturally-occurring atom


1 picometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to (). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
this section lists lengths between 10−12 and 10−11 m (1 pm and 10 pm). *1 pm – distance between
atomic nuclei The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. After the discovery of the neutron ...
in a
white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...
*1 pm – reference value of particle displacement in acoustics *2.4 pm – The
Compton wavelength The Compton wavelength is a quantum mechanical property of a particle. The Compton wavelength of a particle is equal to the wavelength of a photon whose energy is the same as the rest energy of that particle (see mass–energy equivalence). It was ...
of an
electron The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no ...
*5 pm – shorter
X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10  picometers to 10  nanometers, corresponding to frequencies in the range 30&nb ...
wavelengths (approx.)


10 picometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
this section lists lengths between 10−11 and 10−10 m (10 pm and 100 pm). *25 pm – approximate radius of a helium atom, the smallest neutral atom *50 pm – radius of a hydrogen atom *50 pm –
bohr radius The Bohr radius (''a''0) is a physical constant, approximately equal to the most probable distance between the nucleus and the electron in a hydrogen atom in its ground state. It is named after Niels Bohr, due to its role in the Bohr model of an ...
: approximate radius of a hydrogen atom *~50 pm – best resolution of a high-resolution transmission electron microscope *60 pm – radius of a carbon atom *93 pm – length of a
diatomic carbon Diatomic carbon (systematically named dicarbon and 1λ2,2λ2-ethene), is a green, gaseous inorganic chemical with the chemical formula C=C (also written 2or C2). It is kinetically unstable at ambient temperature and pressure, being removed thro ...
molecule *96 pm – H–O bond length in a
water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
molecule


100 picometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
this section lists lengths between 10−10 and 10−9 m (100 pm and 1 nm; 1  Å and 10 Å). *100 pm – 1
ångström The angstromEntry "angstrom" in the Oxford online dictionary. Retrieved on 2019-03-02 from https://en.oxforddictionaries.com/definition/angstrom.Entry "angstrom" in the Merriam-Webster online dictionary. Retrieved on 2019-03-02 from https://www.m ...
*100 pm –
covalent radius The covalent radius, ''r''cov, is a measure of the size of an atom that forms part of one covalent bond. It is usually measured either in picometres (pm) or angstroms (Å), with 1 Å = 100 pm. In principle, the sum of the two coval ...
of sulfur atom *120 pm –
van der Waals radius The van der Waals radius, ''r'', of an atom is the radius of an imaginary hard sphere representing the distance of closest approach for another atom. It is named after Johannes Diderik van der Waals, winner of the 1910 Nobel Prize in Physics, ...
of a neutral
hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
atom *120 pm – radius of a gold atom *126 pm – covalent radius of
ruthenium Ruthenium is a chemical element with the symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemical ...
atom *135 pm – covalent radius of
technetium Technetium is a chemical element with the symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. All available technetium is produced as a synthetic element. Naturally occurring technetium is a spontaneous ...
atom *150 pm – Length of a typical covalent bond ( C–C) *153 pm – covalent radius of
silver Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
atom *155 pm – covalent radius of
zirconium Zirconium is a chemical element with the symbol Zr and atomic number 40. The name ''zirconium'' is taken from the name of the mineral zircon, the most important source of zirconium. The word is related to Persian '' zargun'' (zircon; ''zar-gun'' ...
atom *175 pm – covalent radius of
thulium Thulium is a chemical element with the symbol Tm and atomic number 69. It is the thirteenth and third-last element in the lanthanide series. Like the other lanthanides, the most common oxidation state is +3, seen in its oxide, halides and other c ...
atom *200 pm – highest resolution of a typical
electron microscope An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi ...
*225 pm – covalent radius of caesium atom *280 pm – Average size of the
water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
molecule *298 pm – radius of a caesium atom, calculated to be the largest atomic radius (except possibly francium) *340 pm – thickness of single layer
graphene Graphene () is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure.
*356.68 pm – width of
diamond Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, ...
unit cell In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a unit vector, for example) does not necessaril ...
*403 pm – width of
lithium fluoride Lithium fluoride is an inorganic compound with the chemical formula LiF. It is a colorless solid, that transitions to white with decreasing crystal size. Although odorless, lithium fluoride has a bitter-saline taste. Its structure is analogous to ...
unit cell *500 pm – Width of
protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
α helix *543 pm – silicon lattice spacing *560 pm – width of sodium chloride unit cell *700 pm – width of
glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...
molecule *700 pm – diameter of a buckyball *780 pm – mean width of
quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...
unit cell *820 pm – mean width of
ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaqu ...
unit cell *900 pm – mean width of
coesite Coesite is a form ( polymorph) of silicon dioxide Si O2 that is formed when very high pressure (2–3 gigapascals), and moderately high temperature (), are applied to quartz. Coesite was first synthesized by Loring Coes Jr., a chemist at the ...
unit cell


1 nanometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to (). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−9 and 10−8 m (1 nm and 10 nm). *1 nm – diameter of a carbon nanotube *1 nm – roughly the length of a sucrose molecule, calculated by
Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...
*2.3 nm – length of a phospholipid *2.3 nm – smallest gate oxide thickness in
microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circ ...
s *3 nm – width of a DNA helix *3 nm – flying height of the head of a hard disk *3 nm – , the average half-pitch of a memory cell expected to be manufactured circa 2022 *3.4 nm – length of a DNA turn (10 bp) *3.8 nm – size of an
albumin Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water-soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Albumins ...
molecule *5 nm – size of the gate length of a 16 nm processor *5 nm – , the average half-pitch of a memory cell manufactured circa 2019–2020 *6 nm – length of a phospholipid bilayer *6–10 nm – thickness of cell membrane *6.8 nm – width of a
haemoglobin Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyte ...
molecule *7 nm – diameter of actin filaments *7 nm – the average half-pitch of a memory cell manufactured circa 2018 *10 nm – Thickness of cell wall in
Gram The gram (originally gramme; SI unit symbol g) is a unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram. Originally defined as of 1795 as "the absolute weight of a volume of pure water equal to th ...
-negative
bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...


10 nanometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
this section lists lengths between 10−8 and 10−7 m (10 nm and 100 nm). *10 nm – the average length of a
nanowire A nanowire is a nanostructure in the form of a wire with the diameter of the order of a nanometre (10−9 metres). More generally, nanowires can be defined as structures that have a thickness or diameter constrained to tens of nanometers or less ...
*10 nm – lower size of tobacco smokeAnnis, Patty J. October 1991. Kansas State University. ''Fine Particle POLLUTION''. Figure 1. (tobacco smoke: 10 to ; virus particles: 3 to 50 nm; bacteria: 30 to ; cooking oil smoke: 30 to ; wood smoke: 7 to ) *10 nm – the average half-pitch of a memory cell manufactured circa 2016 2017 *13 nm – the length of the wavelength that is used for
EUV lithography Extreme ultraviolet lithography (also known as EUV or EUVL) is an optical lithography technology used in steppers, machines that make integrated circuits (ICs) for computers and other electronic devices. It uses a range of extreme ultraviolet (EUV) ...
*14 nm – Length of a
porcine circovirus Porcine circovirus (PCV) is a group of four single-stranded DNA viruses that are non-enveloped with an unsegmented circular genome. They are members of the genus ''Circovirus'' that can infect pigs. The viral capsid is icosahedral and approxima ...
*14 nm – the average half-pitch of a memory cell manufactured circa 2013 *15 nm – Length of an antibody *18 nm – diameter of
tobacco mosaic virus ''Tobacco mosaic virus'' (TMV) is a positive-sense single-stranded RNA virus species in the genus ''Tobamovirus'' that infects a wide range of plants, especially tobacco and other members of the family Solanaceae. The infection causes characteri ...
*20 nm – Length of a nanobe, could be one of the smallest forms of life *20–80 nm – thickness of cell wall in Gram-positive bacteria *20 nm – thickness of
bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
l
flagellum A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...
*22 nm – the average half-pitch of a memory cell manufactured circa 2011–2012 *22 nm – Smallest feature size of production
microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circ ...
s in September 2009 *25 nm – diameter of a microtubule *30 nm – lower size of cooking oil smoke *32 nm – the average half-pitch of a memory cell manufactured circa 2009–2010 *40 nm – extreme
ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30  PHz) to 400 nm (750  THz), shorter than that of visible light, but longer than X-rays. UV radiation ...
wavelength *45 nm – the average half-pitch of a memory cell manufactured circa 2007–2008 *50 nm – upper size for airborne
virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...
particles *50 nm – flying height of the head of a hard disk *65 nm – the average half-pitch of a memory cell manufactured circa 2005–2006 *58 nm – height of a T7 bacteriophage *90 nm – Human immunodeficiency virus (HIV) (generally,
virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...
es range in size from 20 nm to 450 nm) *90 nm – the average half-pitch of a memory cell manufactured circa 2002–2003 *100 nm – Length of a
mesoporous silica Mesoporous silica is a form of silica that is characterised by its mesoporous structure, that is, having pores that range from 2 nm to 50 nm in diameter. According to IUPAC's terminology, mesoporosity sits between microporous (50  ...
nanoparticle


100 nanometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−7 and 10−6 m (100 nm and 1  μm). *100 nm – greatest particle size that can fit through a surgical mask *100 nm – 90% of particles in wood
smoke Smoke is a suspension of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-produc ...
are smaller than this. *120 nm – greatest particle size that can fit through a
ULPA ULPA is an acronym for "Ultra-low Penetration Air (filter)". An ULPA filter can remove from the air at least 99.999% of dust, pollen, mold, bacteria and any airborne particles with a minimum particle penetration size of 120 nanometres (0.12  ...
filter *120 nm – diameter of a
human immunodeficiency virus The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immun ...
(HIV) *120 nm – approximate diameter of
SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...
*125 nm – standard depth of pits on
compact disc The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in Oc ...
s (width: 500 nm, length: 850 nm to 3.5 μm) *180 nm – typical length of the
rabies virus Rabies virus, scientific name ''Rabies lyssavirus'', is a neurotropic virus that causes rabies in humans and animals. Rabies transmission can occur through the saliva of animals and less commonly through contact with human saliva. ''Rabies lys ...
*200 nm – typical size of a '' Mycoplasma'' bacterium, among the smallest bacteria *300–400 nm – near
ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30  PHz) to 400 nm (750  THz), shorter than that of visible light, but longer than X-rays. UV radiation ...
wavelength *300 nm – greatest particle size that can fit through a
HEPA HEPA (, high-efficiency particulate air) filter, also known as high-efficiency particulate absorbing filter and high-efficiency particulate arrestance filter, is an efficiency standard of air filters. Filters meeting the HEPA standard must s ...
(high efficiency particulate air) filter (N100 removes up to 99.97% at 0.3 micrometres, N95 removes up to 95% at 0.3 micrometres) *400–420 nm – wavelength of
violet Violet may refer to: Common meanings * Violet (color), a spectral color with wavelengths shorter than blue * One of a list of plants known as violet, particularly: ** ''Viola'' (plant), a genus of flowering plants Places United States * Viol ...
light (see
Color Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are assoc ...
and
Visible spectrum The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' or simply light. A typical human eye will respond to wa ...
) *420–440 nm – wavelength of
indigo Indigo is a deep color close to the color wheel blue (a primary color in the RGB color space), as well as to some variants of ultramarine, based on the ancient dye of the same name. The word "indigo" comes from the Latin word ''indicum'', m ...
light *440–500 nm – wavelength of
blue Blue is one of the three primary colours in the RYB colour model (traditional colour theory), as well as in the RGB (additive) colour model. It lies between violet and cyan on the spectrum of visible light. The eye perceives blue when ...
light *500–520 nm – wavelength of cyan light *520–565 nm – wavelength of
green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a combi ...
light *565–590 nm – wavelength of
yellow Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In the ...
light *590–625 nm – wavelength of
orange Orange most often refers to: *Orange (fruit), the fruit of the tree species '' Citrus'' × ''sinensis'' ** Orange blossom, its fragrant flower *Orange (colour), from the color of an orange, occurs between red and yellow in the visible spectrum * ...
light *625–700 nm – wavelength of
red Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondar ...
light *700–1.4 μm – wavelength of
near-infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...
radiation


1 micrometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to (). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists some items with lengths between 10−6 and 10−5 m (between 1 and 10
micrometre The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
s, or μm). *~0.7–300 μm – wavelength of
infrared radiation Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
*1 μm – the side of a
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
of area 10−12 m2 *1 μm – edge of cube of volume 10−18 m3 (1 fL) *1–10 μm – diameter of a typical
bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were amon ...
*1 μm – length of a
lysosome A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane pr ...
*1–2 μm – anthrax spore *2 μm – length of an average E. coli bacteria *3–4 μm – size of a typical
yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constit ...
cell *5 μm – length of a typical human spermatozoon's head *6 μm – thickness of the tape in a 120-minute (C120) compact cassette *7 μm – diameter of the
nucleus Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom * Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucl ...
of a typical eukaryotic
cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...
*about 7 μm – diameter of human
red blood cell Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...
s *3–8 μm – width of strand of spider web silk *5–10 μm – width of a chloroplast *8–11 μm – size of a ground-level fog or mist dropletBut not
cloud In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may ...
or high-level fog droplets; droplet size increases with altitude. For a contradictory study indicating larger drop sizes even in ground fog, see


10 micrometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−5 m and 10−4 m (10 μm and 100 μm). *10 μm – width of
cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor pe ...
fibre *10 μm – tolerance of a Lego brick *10 μm –
transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...
width of the
Intel 4004 The Intel 4004 is a 4-bit central processing unit (CPU) released by Intel Corporation in 1971. Sold for US$60, it was the first commercially produced microprocessor, and the first in a long line of Intel CPUs. The 4004 was the first significa ...
, the world's first commercial
microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circ ...
*10 μm – mean longest dimension of a human
red blood cell Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...
*5–20 μm –
dust mite House dust mites (HDM, or simply dust mites) are various species of acariform mites belonging to the family Pyroglyphidae that are found in association with dust in dwellings. They are known for causing allergies. Biology Species The curren ...
excreta *10.6 μm – wavelength of light emitted by a
carbon dioxide laser The carbon-dioxide laser (CO2 laser) was one of the earliest gas lasers to be developed. It was invented by Kumar Patel of Bell Labs in 1964 and is still one of the most useful types of laser. Carbon-dioxide lasers are the highest-power contin ...
*15 μm – width of
silk Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the ...
fibre *17 μm – minimum width of a strand of human hair *17.6 μm – one twip, a unit of length in typography *10 to 55 μm – width of
wool Wool is the textile fibre obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have properties similar to animal wool. ...
fibre *25.4 μm – 1/1,000 inch, commonly referred to as 1 mil in the U.S. and 1
thou The word ''thou'' is a second-person singular pronoun in English. It is now largely archaic, having been replaced in most contexts by the word '' you'', although it remains in use in parts of Northern England and in Scots (). ''Thou'' is the ...
in the UK *30 μm – length of a human
skin cell Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different de ...
*50 μm – typical length of '' Euglena gracilis'', a flagellate protist *50 μm – typical length of a human
liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...
cell, an average-sized body cell *50 μm – length of a
silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel ...
particle *60 μm – length of a sperm cell *70 to 180 μm – thickness of paper


100 micrometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−4 m and 10−3 m (100  μm and 1  mm). The term ''myriometre'' (abbr. mom, equivalent to 100 micrometres; frequently confused with the ''
myriametre The following are examples of orders of magnitude for different lengths. __TOC__ Overview Detailed list To help compare different orders of magnitude, the following list describes various lengths between 1.6 \times 10^ metres and 10 ...
'', 10 kilometres) is deprecated; the decimal metric prefix
myrio- Myria- (symbol my) is a now obsolete decimal metric prefix denoting a factor of 104 (ten thousand). It originates from the Greek μύριοι (''mýrioi'') ( myriad). The prefix was part of the original metric system adopted by France in 1795, ...
is obsolete and was not included among the
prefixes A prefix is an affix which is placed before the stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix ''un-'' is added to the word ''happy'', it creates the word ''unhappy''. Particu ...
when the International System of Units was introduced in 1960. *100 μm – 1/10 of a millimetre *100 μm – 0.00394 inches *100 μm – smallest distance that can be seen with the
naked eye Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnifying, light-collecting optical instrument, such as a telescope or microscope, or eye protection. Vision corrected to normal ...
*100 μm – average diameter of a strand of
human hair Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals. The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and fine ...
*100 μm – thickness of a coat of paint *100 μm – length of a
dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in ho ...
particle *120 μm – the geometric mean of the Planck length and the diameter of the
observable universe The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these ob ...
: *120 μm – diameter of a
human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...
ovum *170 μm – length of the largest sperm cell in nature, belonging to the '' Drosophila bifurca'' fruit fly *181 μm – maximum width of a strand of human hair *100–400 μm – length of Demodex mites living in human hair follicles *175–200 μm – typical thickness of a
solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.
. *200 μm – typical length of '' Paramecium caudatum'', a ciliate protist *200 μm – nominal width of the smallest commonly available mechanical pencil lead (0.2 mm) *250–300 μm – length of a
dust mite House dust mites (HDM, or simply dust mites) are various species of acariform mites belonging to the family Pyroglyphidae that are found in association with dust in dwellings. They are known for causing allergies. Biology Species The curren ...
*340 μm – length of a
pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the ...
on a 17-inch monitor with a resolution of 1024×768 *500 μm – typical length of ''
Amoeba proteus ''Amoeba proteus'' is a large species of amoeba closely related to another genus of giant amoebae, '' Chaos''. As such, the species is sometimes given the alternative scientific name ''Chaos diffluens''. This protozoan uses extensions called pseu ...
'', an amoeboid protist * *500 μm – average length of a grain of
sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class o ...
*500 μm – average length of a grain of
salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...
*500 μm – average length of a grain of sugar *560 μm – thickness of the central area of a human
cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...
*750 μm – diameter of a
Thiomargarita namibiensis ''Thiomargarita namibiensis'' is a Gram-negative coccoid bacterium, found in the ocean sediments of the continental shelf of Namibia. It is the second largest bacterium ever discovered, as a rule in diameter, but sometimes attaining . Cells of ...
, the largest bacteria known *760 μm – thickness of an
identification card An identity document (also called ID or colloquially as papers) is any document that may be used to prove a person's identity. If issued in a small, standard credit card size form, it is usually called an identity card (IC, ID card, citizen ca ...


1 millimetre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to (). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−3 m and 10−2 m (1 mm and 1 cm). *1.0 mm – 1/1,000 of a metre *1.0 mm – 0.03937 inches or 5/127 (exactly) *1.0 mm – side of a
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
of area 1 mm² *1.0 mm – diameter of a pinhead *1.5 mm – average length of a flea *2.54 mm – distance between pins on old dual in-line package (DIP) electronic components *5 mm – length of an average red ant *5 mm – diameter of an average grain of rice *
5.56×45mm NATO The 5.56×45mm NATO (official NATO nomenclature 5.56 NATO, but often pronounced "five-five-six") is a rimless bottlenecked intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. It consists of the SS109, L110, an ...
– standard ammunition size *6 mm – approximate width of a pencil *7 mm – length of a ''
Paedophryne amauensis ''Paedophryne amauensis'' is a species of microhylid frog endemic to eastern Papua New Guinea. At in snout-to-vent length, it is considered the world's smallest known vertebrate. (See also Ecological guild.) The species was listed in the '' ...
'', the smallest-known vertebrate *7.1 mm – length of a sunflower seed * 7.62×51mm NATO – common military ammunition size *8 mm – width of old-format home movie film *8 mm – length of a ''
Paedocypris progenetica ''Paedocypris progenetica'' is a species of tiny cyprinid fish endemic to the Indonesian islands of Sumatra and Bintan where it is found in peat swamps and blackwater streams. It was discovered by Singaporean ichthyologist Heok Hui Tan. He ha ...
'', the smallest-known fish


1 centimetre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to (). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10−2 m and 10−1 m (1 cm and 1 dm). *1 cm – 10
millimetres 330px, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is between 1 meter to 1 millimeter. The millimetre (American and British English spelling differences#-re, -er, ...
*1 cm – 0.39 inches *1 cm – edge of a
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
of area 1 cm2 *1 cm – edge of a cube of volume 1 mL *1 cm – length of a coffee bean *1 cm – approximate width of average fingernail *1.2 cm – length of a bee *1.2 cm – diameter of a die *1.5 cm – length of a very large mosquito *1.6 cm – length of a Jaragua Sphaero, a very small reptile *1.7 cm – length of a Thorius arboreus, the smallest salamander *2 cm – approximate width of an adult human finger *2.54 cm – 1 inch *3.08568 cm – 1 attoparsec (10−18
parsec The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (au), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, an ...
s) *3.4 cm – length of a quail egg *3.5 cm – width of film commonly used in motion pictures and still photography *3.78 cm – amount of distance the Moon moves away from Earth each year *4.3 cm – minimum diameter of a golf ball *5 cm – usual diameter of a chicken egg *5 cm – height of a hummingbird, the smallest-known bird *5.5 × 5.5 × 5.5 cm – dimensions of a 3x3x3 Rubik's cube *6.1 cm – average height of an apple *7.3–7.5 cm – diameter of a baseball *8.6 cm × 5.4 cm – dimensions of a standard credit card *9 cm – length of a speckled padloper, the smallest-known turtle


1 decimetre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to (). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10
centimetre 330px, Different lengths as in respect to the Electromagnetic spectrum, measured by the Metre and its deriveds scales. The Microwave are in-between 1 meter to 1 millimeter. A centimetre (international spelling) or centimeter (American spellin ...
s and 100 centimetres (10−1 metre and 1 metre).


Conversions

10 centimetres (abbreviated to 10 cm) is equal to: *1
decimetre The decimetre (symbol dm) or decimeter (American English) is a unit of length in the International System of Units (SI), equal to one tenth of a metre, ten centimetres, 100 millimetres or 3.937 inches. The common non-SI metric unit of volume, ...
(dm), a term not in common use (1 L = 1 dm3.) *100 millimetres *3.9 inches *a side of a
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
of area 0.01 m2 *the edge of a cube with a volume of m3 (1 L)


Wavelengths

*10 cm = 1.0 dm – wavelength of the highest UHF radio frequency, 3 GHz *12 cm = 1.2 dm – wavelength of the 2.45 GHz ISM radio band *21 cm = 2.1 dm – wavelength of the 1.4 GHz hydrogen emission line, a
hyperfine In atomic physics, hyperfine structure is defined by small shifts in otherwise degenerate energy levels and the resulting splittings in those energy levels of atoms, molecules, and ions, due to electromagnetic multipole interaction between the nuc ...
transition of the hydrogen atom *100 cm = 10 dm – wavelength of the lowest UHF radio frequency, 300 MHz


Human-defined scales and structures

*10.16 cm = 1.016 dm – 1 hand used in measuring height of horses (4 inches) *12 cm = 1.2 dm – diameter of a compact disc (CD) (= 120 mm) *15 cm = 1.5 dm – length of a Bic pen with cap on *22 cm = 2.2 dm – diameter of a typical association football (soccer ball) *30 cm = 3 dm – typical school-use ruler length (= 300 mm) *30.48 cm = 3.048 dm – 1 foot (measure) *60 cm = 6 dm – standard depth (front to back) of a domestic kitchen worktop in Europe (= 600 mm) *90 cm = 9 dm – average length of a rapier, a fencing sword *91.44 cm = 9.144 dm – one
yard The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3  feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...
(measure)


Nature

*10 cm = 1 dm – diameter of the human cervix upon entering the second stage of labour *11 cm = 1.1 dm – diameter of an average potato in the US *13 cm = 1.3 dm – body length of a Goliath birdeater *15 cm = 1.5 dm – approximate size of largest beetle species *19 cm = 1.9 dm – length of a banana *26.3 cm = 2.6 dm – length of average male human foot *29.98 cm = 2.998 dm – distance light in vacuum travels in one
nanosecond A nanosecond (ns) is a unit of time in the International System of Units (SI) equal to one billionth of a second, that is, of a second, or 10 seconds. The term combines the SI prefix ''nano-'' indicating a 1 billionth submultiple of an SI unit ( ...
*30 cm = 3.0 dm – maximum leg length of a Goliath birdeater *31 cm = 3.1 dm – wingspan of largest butterfly species ''Ornithoptera alexandrae'' *46 cm = 4.6 dm – length of an average domestic cat *50 to 65 cm = 5–6.5 dm – a coati's tail *66 cm = 6.6 dm – length of the longest pine cones (produced by the sugar pine)


Astronomical

*84 cm = 8.4 dm – approximate diameter of 2008 TS26, a meteoroid


1 metre

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between one
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
and ten metres. Light, in vacuum, travels 1 metre in , or of a second.


Conversions

1
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
is: *10
decimetre The decimetre (symbol dm) or decimeter (American English) is a unit of length in the International System of Units (SI), equal to one tenth of a metre, ten centimetres, 100 millimetres or 3.937 inches. The common non-SI metric unit of volume, ...
s *100
centimetre 330px, Different lengths as in respect to the Electromagnetic spectrum, measured by the Metre and its deriveds scales. The Microwave are in-between 1 meter to 1 millimeter. A centimetre (international spelling) or centimeter (American spellin ...
s *1,000 millimetres *39.37 inches *3.28
feet The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
*1.1
yard The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3  feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...
s *side of
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
with area 1 m2 *edge of cube with surface area 6 m2 and volume 1 m3 *radius of
circle A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre. Equivalently, it is the curve traced out by a point that moves in a plane so that its distance from a given point is con ...
with area π m2 *radius of
sphere A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is th ...
with surface area 4π m2 and volume 4/3π m3


Human-defined scales and structures

*1 m – approximate height of the top part of a doorknob on a door *1 m – diameter of a very large beach ball *1.435 m – standard gauge of railway track used by about 60% of railways in the world = 4 ft 8 in *2.5 m – distance from the floor to the ceiling in an average residential house *2.7 m – length of the Starr Bumble Bee II, the smallest plane *2.77–3.44 m – wavelength of the broadcast radio FM band 87–108 MHz *3.05 m – the length of an old Mini *8.38 m – the length of a London Bus (
AEC Routemaster The AEC Routemaster is a front-engined double-decker bus that was designed by London Transport and built by the Associated Equipment Company (AEC) and Park Royal Vehicles. The first prototype was completed in September 1954 and the last one ...
)


Sports

*2.44 m – height of an association football goal *2.45 m – highest high jump by a human (Javier Sotomayor) *3.05 m – (10 feet) height of the basket in basketball *8.95 m – longest long jump by a human (Mike Powell)


Nature

*1 m – height of ''
Homo floresiensis ''Homo floresiensis'' also known as "Flores Man"; nicknamed "Hobbit") is an extinct species of small archaic human that inhabited the island of Flores, Indonesia, until the arrival of modern humans about 50,000 years ago. The remains of an in ...
'' (the "Hobbit") *1.15 m – a pizote (mammal) *1.63 m – (5 feet 4 inches) (or 64 inches) – height of average U.S. female human (source: U.S. Centers for Disease Control and Prevention (CDC)) *1.75 m – (5 feet 8 inches) – height of average U.S. male human (source: U.S. CDC as per female above) *2.5 m – height of a sunflower *2.72 m – (8 feet 11 inches) – tallest-known human (Robert Wadlow) *3.63 m – the record wingspan]for living birds (a wandering albatross) *5 m – length of an elephant *5.2 m – height of a giraffe *5.5 m – height of a ''
Baluchitherium ''Paraceratherium'' is an extinct genus of hornless rhinoceros. It is one of the largest terrestrial mammals that has existed and lived from the early to late Oligocene epoch (34–23 million years ago). The first fossils were discovered ...
'', the largest land mammal ever lived *6.5 m – wingspan of ''
Argentavis ''Argentavis magnificens'' was among the largest flying birds ever to exist. While it is still considered the heaviest flying bird of all time, ''Argentavis'' was likely surpassed in wingspan by '' Pelagornis sandersi'' which is estimated to have ...
'', the largest flying bird known *7.4 m – wingspan of ''
Pelagornis ''Pelagornis'' is a widespread genus of prehistoric pseudotooth birds. These were probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertain ...
,'' the bird with longest wingspan ever. *7.5 m – approximate length of the human gastrointestinal tract


Astronomical

*3–6 m – approximate diameter of , a meteoroid *4.1 m – diameter of
2008 TC3 (Catalina Sky Survey temporary designation 8TA9D69) was an , diameter asteroid that entered Earth's atmosphere on October 7, 2008. It exploded at an estimated above the Nubian Desert in Sudan. Some 600 meteorites, weighing a total of , we ...
, a small asteroid that flew into the Earth's atmosphere on October 7, 2008


1 decametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to 10 
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (101 m). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10 and 100 metres.


Conversions

10 metres (very rarely termed a
decametre A decametre ( International spelling as used by the International Bureau of Weights and Measures and by most English speaking countries, United States spelling dekameter or decameter,), symbol dam ("da" for the SI prefix deca-, "m" for the SI ...
which is abbreviated as dam) is equal to: *10 metres *100
decimetre The decimetre (symbol dm) or decimeter (American English) is a unit of length in the International System of Units (SI), equal to one tenth of a metre, ten centimetres, 100 millimetres or 3.937 inches. The common non-SI metric unit of volume, ...
s *1,000
centimetre 330px, Different lengths as in respect to the Electromagnetic spectrum, measured by the Metre and its deriveds scales. The Microwave are in-between 1 meter to 1 millimeter. A centimetre (international spelling) or centimeter (American spellin ...
s *10,000 millimetres *32.8
feet The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
*11
yards The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3  feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...
*side of a
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
with area 100 m²


Human-defined scales and structures

*10 metres – wavelength of the highest shortwave radio frequency, 30 M Hz *23 metres – height of the obelisk of the Place de la Concorde, Paris, France *25 metres – wavelength of the broadcast radio shortwave band at 12 MHz *29 metres – height of the lighthouse at Savudrija, Croatia *31 metres – wavelength of the broadcast radio shortwave band at 9.7 MHz *34 metres – height of the Split Point Lighthouse in Aireys Inlet, Victoria, Australia *40 metres – average depth beneath the seabed of the Channel tunnel *49 metres – wavelength of the broadcast radio shortwave band at 6.1 MHz *50 metres – length of a road train *55 metres – height of the
Leaning Tower of Pisa The Leaning Tower of Pisa ( it, torre pendente di Pisa), or simply, the Tower of Pisa (''torre di Pisa'' ), is the ''campanile'', or freestanding bell tower, of Pisa Cathedral. It is known for its nearly four-degree lean, the result of an unst ...
*62.5 metres – height of
Pyramid of Djoser The pyramid of Djoser (or Djeser and Zoser), sometimes called the Step Pyramid of Djoser, is an archaeological site in the Saqqara necropolis, Egypt, northwest of the ruins of Memphis. The 6-tier, 4-sided structure is the earliest colossal stone ...
*64 metres – wingspan of a Boeing 747-400 *69 metres – wingspan of an Antonov An-124 Ruslan *70 metres – length of the Bayeux Tapestry *70 metres – width of a typical association football field *77 metres – wingspan of a Boeing 747-8 *88.4 metres – wingspan of an Antonov An-225 ''Mriya'' transport aircraft *93 metres – height of the Statue of Liberty *96 metres – height of Big Ben *100 metres – wavelength of the lowest shortwave radio frequency, 3 MHz


Sports

*11 metres – approximate width of a doubles tennis court *15 metres – width of a standard FIBA basketball court *15.24 metres – width of an NBA]basketball court (50 feet) *18.44 metres – distance between the front of the pitcher's rubber and the rear point of home plate on a baseball field (60 feet, 6 inches) *20 metres – length of cricket pitch (22 yards) *27.43 metres – distance between bases on a baseball field (90 feet) *28 metres – length of a standard FIBA basketball court *28.65 metres – length of an NBA basketball court (94 feet) *49 metres – width of an American football field (53 yards) *59.436 metres – width of a Canadian football field (65 yards) *70 metres – typical width of a soccer field *91 metres – length of an American football field (100 yards, measured between the goal lines)


Nature

*10 metres – average length of human digestive tract *12 metres – length of a whale shark, largest living fish *12 metres – wingspan of a '' Quetzalcoatlus'', a pterosaur *13 metres – length of a giant squid and colossal squid, the largest living invertebrates *15 metres – approximate distance the tropical circles of latitude are moving towards the equator and the polar circles are moving towards the poles each year due to a natural, gradual decrease in the Earth's axial tilt *18 metres – height of a ''
Sauroposeidon ''Sauroposeidon'' ( ; meaning "lizard earthquake god", after the Greek god Poseidon) is a genus of sauropod dinosaur known from several incomplete specimens including a bone bed and fossilized trackways that have been found in the U.S. states of ...
'', the tallest-known dinosaur *20 metres – length of a ''
Leedsichthys ''Leedsichthys'' is an extinct genus of pachycormid fish that lived in the oceans of the Middle to Late Jurassic.Liston, JJ (2004). An overview of the pachycormiform ''Leedsichthys''. In: Arratia G and Tintori A (eds) Mesozoic Fishes 3 - System ...
'', the largest-known fish to have lived *21 metres – height of
High Force High Force is a waterfall on the River Tees, near Middleton-in-Teesdale, Teesdale, England. The waterfall is within the North Pennines Area of Outstanding Natural Beauty (AONB) and the European Geopark. The waterfall is part of the historic coun ...
waterfall in England *33 metres – length of a blue whale, the largest animal on earth, living or extinct, in terms of mass *39 metres – length of a '' Supersaurus'', the longest-known dinosaur and longest vertebrate *52 metres – height of Niagara Falls *55 metres – length of a bootlace worm, the longest-known animal *83 metres – height of a Western hemlock


Astronomical

*30 metres – diameter of , a rapidly spinning meteoroid *30.8568 metres – 1 femtoparsec *32 metres – approximate diameter of 2008 HJ, a small meteoroid


1 hectometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to 100 
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (102 m). To compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
this section lists lengths between 100 metres and 1,000 metres (1 kilometre).


Conversions

100 metres (sometimes termed a hectometre) is equal to: *328
feet The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
*one side of a 1 hectare square *a fifth of a modern li, a Chinese unit of measurement *the approximate distance travelled by light in 300
nanosecond A nanosecond (ns) is a unit of time in the International System of Units (SI) equal to one billionth of a second, that is, of a second, or 10 seconds. The term combines the SI prefix ''nano-'' indicating a 1 billionth submultiple of an SI unit ( ...
s


Human-defined scales and structures

*100 metres – wavelength of the highest medium wave radio frequency, 3 MHz *100 metres – spacing of location marker posts on British motorways *138.8 metres – height of the
Great Pyramid of Giza The Great Pyramid of Giza is the biggest Egyptian pyramid and the tomb of Fourth Dynasty pharaoh Khufu. Built in the early 26th century BC during a period of around 27 years, the pyramid is the oldest of the Seven Wonders of the Ancient Worl ...
(Pyramid of Cheops) *139 metres – height of the world's tallest roller coaster, Kingda Ka *187 metres – shortest wavelength of the broadcast radio AM band, 1600 kHz *202 metres – length of the
Széchenyi Chain Bridge The Széchenyi Chain Bridge ( hu, Széchenyi lánchíd ) is a chain bridge that spans the River Danube between Buda and Pest, the western and eastern sides of Budapest, the capital of Hungary. Designed by English engineer William Tierney Clark ...
connecting Buda and Pest *318 metres – height of The New York Times Building *318.9 metres – height of the Chrysler Building *328 metres – height of Auckland's Sky Tower, the tallest free-standing structure in the Southern Hemisphere *330 metres – height of the
Eiffel Tower The Eiffel Tower ( ; french: links=yes, tour Eiffel ) is a wrought-iron lattice tower on the Champ de Mars in Paris, France. It is named after the engineer Gustave Eiffel, whose company designed and built the tower. Locally nicknamed "' ...
(including antenna) *341 metres – height of the world's tallest bridge, the Millau Viaduct *390 metres – height of the Empire State Building *400–800 metres – heights of the world's tallest skyscrapers of the past 80 years *458 metres – length of the Knock Nevis, the world's largest supertanker *553.33 metres – height of the CN Tower *555 metres – longest wavelength of the broadcast radio AM band, 540 kHz *630 metres – height of the KVLY-TV mast, second-tallest structure in the world *646 metres – height of the Warsaw radio mast, the world's tallest structure until its collapse in 1991 *828 metres – height of Burj Khalifa, world's tallest structure on 17 January 2009 *1,000 metres – wavelength of the lowest mediumwave radio frequency, 300 kHz


Sports

*100 metres – the distance a very fast human can run in about 10 seconds *100.584 metres – length of a Canadian football field between the goal lines (110
yard The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3  feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...
s) *91.5 metres – 137 metres – length of a soccer field *105 metres – length of football pitch (UEFA stadium categories 3 and 4) *105 metres – length of a typical football field *109.73 metres – total length of an American football field (120 yards, including the end zones) *110–150 metres – the width of an Australian football field *135–185 metres – the length of an Australian football field *137.16 metres – total length of a Canadian football field, including the end zones (150 yards)


Nature

*115.5 metres – height of the world's tallest tree in 2007, the Hyperion sequoia *310 metres – maximum depth of Lake Geneva *340 metres – distance sound travels in air at sea level in one second; see Speed of sound *979 metres – height of the Salto Angel, the world's highest free-falling waterfall (Venezuela) *1500 metres – distance sound travels in water in one second


Astronomical

*270 metres – length of
99942 Apophis 99942 Apophis is a near-Earth asteroid and potentially hazardous asteroid with a diameter of that caused a brief period of concern in December 2004 when initial observations indicated a probability up to 2.7% that it would hit Earth on April&nb ...
*535 metres – length of
25143 Itokawa 25143 Itokawa (provisional designation ) is a sub-kilometer near-Earth object of the Apollo group and a potentially hazardous asteroid. It was discovered by the LINEAR program in 1998 and later named after Japanese rocket engineer Hideo Itokawa ...
, a small asteroid visited by a spacecraft


1 kilometre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to  
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (103 m). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 1 kilometre and 10  kilometres (103 and 104
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s).


Conversions

1 kilometre (unit symbol km) is equal to: *1,000
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s *0.621371 miles *1,093.61
yard The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3  feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...
s *3,280.84
feet The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
*39,370.1 inches *100,000
centimetre 330px, Different lengths as in respect to the Electromagnetic spectrum, measured by the Metre and its deriveds scales. The Microwave are in-between 1 meter to 1 millimeter. A centimetre (international spelling) or centimeter (American spellin ...
s *1,000,000 millimetres *Side of a
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
of area 1 km2 *Radius of a
circle A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre. Equivalently, it is the curve traced out by a point that moves in a plane so that its distance from a given point is con ...
of area π km2


Human-defined scales and structures

*1 km – wavelength of the highest
long wave In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band. The term is historic, dating from the e ...
radio frequency,
300 __NOTOC__ Year 300 ( CCC) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Valerius (or, less frequently, year 1053 ''Ab ...
kHz *1.280 km – span of the Golden Gate Bridge (distance between towers) *1.609 km – 1 statute mile *1.852 km – 1 nautical mile, equal to 1
arcminute A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The n ...
of
latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...
at the surface of the Earth *1.991 km – span of the
Akashi Kaikyō Bridge The is a suspension bridge which links the city of Kobe on the Japanese island of Honshu to Iwaya on Awaji Island. It is part of the Kobe-Awaji-Naruto Expressway, and crosses the busy and turbulent Akashi Strait (''Akashi Kaikyō'' in Japanese ...
*2.309 km – axial length of the
Three Gorges Dam The Three Gorges Dam is a hydroelectric gravity dam that spans the Yangtze River by the town of Sandouping, in Yiling District, Yichang, Hubei province, central China, downstream of the Three Gorges. The Three Gorges Dam has been the world' ...
, the largest
dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...
in the world *3.991 km – length of the
Akashi Kaikyō Bridge The is a suspension bridge which links the city of Kobe on the Japanese island of Honshu to Iwaya on Awaji Island. It is part of the Kobe-Awaji-Naruto Expressway, and crosses the busy and turbulent Akashi Strait (''Akashi Kaikyō'' in Japanese ...
, longest suspension bridge in the world *5.072 km – height of
Tanggula Mountain Pass The Tanggu La, Tangla Pass, or Tanggu Pass (; bo, གདང་ལ) is a wide mountain pass in Southwest China over in elevation, which utilized by both the Qinghai–Tibet Highway and Qinghai–Tibet Railway to cross the Tanggula Mountains. T ...
, below highest peak in the
Tanggula Mountains The Tanggula ( Chinese: , p ''Tánggǔlāshān'', or , p ''Tánggǔlāshānmài''), Tangla, Tanglha, or Dangla Mountains (Tibetan: , w ''Gdang La'', z ''Dang La'') are a mountain range in the central part of the ...
, highest
railway Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...
pass in the world *5.727 km – height of Cerro Aucanquilcha, highest road in the world, located in
Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
* 98 airports have paved runways from 4 km to 5.5 km in length. *8 km – length of
Palm Jebel Ali Palm Jebel Ali () is an artificial archipelago in Dubai, United Arab Emirates which began construction in October 2002, was originally planned to be completed by mid-2008 and has been on hold since. Creative Kingdom provided master planning ser ...
, an
artificial island An artificial island is an island that has been constructed by people rather than formed by natural means. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure to those th ...
built off the coast of
Dubai Dubai (, ; ar, دبي, translit=Dubayy, , ) is the most populous city in the United Arab Emirates (UAE) and the capital of the Emirate of Dubai, the most populated of the 7 emirates of the United Arab Emirates.The Government and Politics of ...
*9.8 km – length of
The World In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently in different fields. Some conceptions see the worl ...
, an artificial archipelago that is also built off the coast of
Dubai Dubai (, ; ar, دبي, translit=Dubayy, , ) is the most populous city in the United Arab Emirates (UAE) and the capital of the Emirate of Dubai, the most populated of the 7 emirates of the United Arab Emirates.The Government and Politics of ...
, whose islands resemble a
world map A world map is a map of most or all of the surface of Earth. World maps, because of their scale, must deal with the problem of projection. Maps rendered in two dimensions by necessity distort the display of the three-dimensional surface of th ...


Geographical

*1.637 km – deepest dive of Lake Baikal in
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
, the world's largest freshwater
lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
*2.228 km – height of
Mount Kosciuszko Mount Kosciuszko ( ; Ngarigo: , ), previously spelled Mount Kosciusko, is mainland Australia's tallest mountain, at 2,228 metres (7,310 ft) above sea level. It is located on the Main Range of the Snowy Mountains in Kosciuszko National ...
, highest point on mainland Geography of Australia, Australia *Most of Manhattan is from 3 to 4 km wide. *4.810 km – height of Mont Blanc, highest peak in the Alps *4.884 km – height of Carstensz Pyramid, highest peak in Oceania *4.892 km – height of Mount Vinson, highest peak in Antarctica *5.610 km – height of Mount Damavand, highest peak in Iran *5.642 km – height of Mount Elbrus, highest peak in Europe *5.895 km – height of Mount Kilimanjaro, highest peak in Africa *6.081 km – height of Mount Logan, highest peak in Canada *6.190 km – height of Denali, highest peak in North America *6.959 km – height of Aconcagua, highest peak in South America *7.5 km – depth of Cayman Trench, deepest point in the Caribbean Sea *8.848 km – height of Mount Everest, highest peak on Earth, on the border between Nepal and China


Astronomical

*1 km – diameter of 1620 Geographos *1 km – very approximate size of the smallest-known moons of Jupiter *1.4 km – diameter of Dactyl (asteroid), Dactyl, the first confirmed asteroid moon *4.8 km – diameter of 5535 Annefrank, an inner belt asteroid *5 km – diameter of 3753 Cruithne *5 km – length of PSR B1257+12 *8 km – diameter of Themisto (moon), Themisto, one of Jupiter's moons *8 km – diameter of the Vela Pulsar *8.6 km – diameter of Callirrhoe (moon), Callirrhoe, also known as Jupiter XVII *9.737 km – length of PSR B1919+21


10 kilometres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 10 and 100 kilometres (104 to 105
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s). The ''myriametre'' (Website based on ''Alte Meß- und Währungssysteme aus dem deutschen Sprachgebiet'', ) (sometimes also spelled ''myriometre''; 10,000 metres) is a deprecated unit name; the decimal metric prefix myria- (sometimes also written as myrio-) is obsolete and not included among the
prefixes A prefix is an affix which is placed before the stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix ''un-'' is added to the word ''happy'', it creates the word ''unhappy''. Particu ...
when the International System of Units was introduced in 1960.


Conversions

10 kilometres is equal to: *10,000
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s *6.2 miles *1 ''mil (the Scandinavian mile)'', now standardized as 10 km: **1 mil, the unit of measure commonly used in Norway and SwedenHaugen, Einar, ''Norwegian English Dictionary,'' 1965, Oslo: Universitetsforlaget and Madison: University of Wisconsin Press, s.v. mil used to be 11,295 m in Norway and 10,688 m in Sweden. *''Parasang, farsang'', unit of measure commonly used in Iran and Turkey


Sports

*42.195 km – length of the marathon


Human-defined scales and structures

*18 km – cruising altitude of Concorde *27 km – circumference of the Large Hadron Collider, the largest and highest energy particle accelerator *34.668 km – highest manned balloon flight (Malcolm D. Ross and Victor E. Prather on 4 May 1961) *38.422 km – length of the Second Lake Pontchartrain Causeway in Louisiana, US *39 km – undersea portion of the Channel tunnel *53.9 km – length of the Seikan Tunnel, , the longest rail tunnel in the world *77 km – rough total length of the Panama Canal


Geographical

*10 km – height of Mauna Kea in Hawaii, measured from its base on the ocean floor *11 km – deepest-known point of the ocean, Challenger Deep in the Mariana Trench *11 km – average height of the troposphere *14 km – width of the Gibraltar strait *21 km – length of Manhattan *23 km – depth of the 1931 Dogger Bank earthquake, largest earthquake ever recorded in the United Kingdom, in 1931 at the Dogger Bank of the North Sea *34 km – narrowest width of the English Channel at the Strait of Dover *50 km – approximate height of the stratosphere *90 km – width of the Bering Strait


Astronomical

*10 km – diameter of the most massive neutron stars (3–5 solar masses) *13 km – mean diameter of Deimos (moon), Deimos, the smaller moon of Mars *20 km – diameter of the least massive neutron stars (1.44 solar masses) *20 km – diameter of Leda (moon), Leda, one of Jupiter's moons *20 km – diameter of Pan (moon), Pan, one of Saturn's moons *22 km – diameter of Phobos (moon), Phobos, the larger moon of Mars *27 km – height of Olympus Mons above the Mars reference level, the highest-known mountain of the Solar System *30.8568 km – 1 picoparsec *43 km – diameter difference of Earth's equatorial bulge *66 km – diameter of Naiad (moon), Naiad, the innermost of Neptune's moons


100 kilometres

A length of ''100 kilometres'' (about 62 miles), as a rough amount, is relatively common in measurements on Earth and for some astronomical objects. It is the altitude at which the Fédération Aéronautique Internationale, FAI defines spaceflight to begin. To help compare
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths between 100 and 1,000 kilometres (105 and 106
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s).


Conversions

A distance of 100 kilometres is equal to about 62 miles (or ).


Human-defined scales and structures

*100 km – the Karman line: the official boundary of outer space *105 km – distance from Giridih to Bokaro Steel City, Bokaro *109 km – length of High Speed 1 between London and the Channel Tunnel *130 km – range of a Scud-A missile *163 km – length of the Suez Canal *164 km – length of the Danyang–Kunshan Grand Bridge *213 km – length of Paris Métro *217 km – length of the Grand Union Canal *223 km – length of the Madrid Metro *300 km – range of a Scud-B missile *386 km – altitude of the International Space Station *408 km – length of the London Underground (active track) *460 km – distance from London to Paris *470 km – distance from Dublin to London as the crow flies *600 km – range of a Scud-C missile *600 km – height above ground of the Hubble Space Telescope *804.67 km – (500 miles) distance of the Indy 500 automobile race


Geographical

*111 km – distance covered by one degree of
latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...
on Earth's surface *180 km – distance between Mumbai and Nashik *203 km – length of Sognefjorden, the third-largest fjord in the world *220 km – distance between Pune and Nashik *240 km – widest width of the English Channel *430 km – length of the Pyrenees *500 km – widest width of Geography of Sweden, Sweden from east to west *550 km – distance from San Francisco to Los Angeles as the crow flies *560 km – distance of Bordeaux–Paris, formerly the longest one-day professional cycling race *590 km – length of land boundary between Geography of Finland, Finland and Geography of Sweden, Sweden *724 km – length of the Om River *871 km – distance from Sydney to Melbourne (along the Hume Highway) *897 km – length of the River Douro *900 km – distance from Berlin to Stockholm *956 km – distance from Washington, D.C. to Chicago, Illinois as the crow flies


Astronomical

*100 km – the altitude at which the Fédération Aéronautique Internationale, FAI defines spaceflight to begin *167 km – diameter of Amalthea (moon), Amalthea, one of Jupiter's inner moons *200 km – width of Valles Marineris *220 km – diameter of Phoebe (moon), Phoebe, the largest of Saturn's outer moons *300 km – the approximate distance travelled by light in one millisecond *340 km – diameter of Nereid (moon), Nereid, the third-largest moon of Neptune *350 km – lower bound of Low Earth orbit *420 km – diameter of Proteus (moon), Proteus, the second-largest moon of Neptune *468 km – diameter of the asteroid 4 Vesta *472 km – diameter of Miranda (moon), Miranda, one of Uranus's major moons *974.6 km – greatest diameter of Ceres (dwarf planet), 1 Ceres, the largest Solar System asteroid


1 megametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to  
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (106 m). To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths starting at 106 m (#1 megametre, 1 Mm or 1,000 kilometre, km).


Conversions

1 megametre is equal to: *1 E+6 m (one million metres) *approximately 621.37 miles *Side of
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
with area 1,000,000 km2


Human-defined scales and structures

*2.100 Mm – Length of proposed Iran-Pakistan-India gas pipeline, gas pipeline from Iran to India via Pakistan *2.100 Mm – Distance from Casablanca to Rome *2.288 Mm – Length of the official Alaska Highway when it was built in the 1940s *3.069 Mm – Length of Interstate 95 (from Houlton, Maine to Miami, Florida) *3.846 Mm – Length of U.S. Route 1 (from Fort Kent, Maine to Key West, Florida) *5.000 Mm – Width of the United States *5.007 Mm – Estimated length of Interstate 90 (Seattle, Washington to Boston, Massachusetts) *5.614 Mm – Length of the Australian Dingo Fence *6.371 Mm – Global-average Earth radius *6.4 Mm – Length of the Great Wall of China *7.821 Mm – Length of the Trans-Canada Highway, the world's longest national highway (from Victoria, British Columbia to St. John's, Newfoundland) *8.836 Mm – Road distance between Prudhoe Bay, Alaska, and Key West, Florida, the endpoints of the U.S. road network *8.852 Mm – Aggregate length of the Great Wall of China, including trenches, hills and rivers *9.259 Mm – Length of the Trans-Siberian railway


Sports

*The Munda Biddi Trail in Western Australia, WA, Australia is over 1,000 km long – the world's longest off-road cycle trail *1.200 Mm – the length of the Paris–Brest–Paris bicycling event *Several endurance auto races are, or were, run for 1,000 km: **Bathurst 1000 **1000 km Brands Hatch **1000 km Buenos Aires **1000 km Donington **1000 km Monza **1000 km Nürburgring **1000 km Silverstone **1000 km Spa **1000 km Suzuka **1000 km Zeltweg


Geographical

*1.010 Mm – Distance from San Diego to El Paso as the crow flies *2.000 Mm – Distance from Beijing to Hong Kong as the crow flies *2.800 Mm – Narrowest width of Atlantic Ocean (Brazil-West Africa) *2.850 Mm – Length of the Danube river *2.205 Mm – Length of Geography of Sweden, Sweden's total land boundaries *2.515 Mm – Length of Geography of Norway, Norway's total land boundaries *3.690 Mm – Length of the Volga river, longest in Europe *4.350 Mm – Length of the Yellow River *4.800 Mm – Widest width of Atlantic Ocean (U.S.-Northern Africa) *5.100 Mm – Distance from Dublin to New York City, New York as the crow flies *6.270 Mm – Length of the Mississippi River, Mississippi-Missouri River system *6.380 Mm – Length of the Yangtze River *6.400 Mm – Length of the Amazon River *6.758 Mm – Length of the Nile River, Nile system, longest on Earth *8.200 Mm – Approximate Distance from Dublin to San Francisco


Astronomical

*1.000 Mm – Estimated shortest axis of Ellipsoid, triaxial dwarf planet *1.186 Mm – Diameter of Charon (moon), Charon, the largest moon of Pluto *1.280 Mm – Diameter of the trans-Neptunian object 50000 Quaoar *1.436 Mm – Diameter of Iapetus (moon), Iapetus, one of Saturn's major moons *1.578 Mm – Diameter of Titania (moon), Titania, the largest of Uranus's moons *1.960 Mm – Estimated longest axis of Haumea (dwarf planet), Haumea *2.326 Mm – Diameter of the dwarf planet Eris (dwarf planet), Eris, the largest trans-Neptunian object found to date *2.376 Mm – Diameter of Pluto *2.707 Mm – Diameter of Triton (moon), Triton, largest moon of Neptune *3.122 Mm – Diameter of Europa (moon), Europa, the smallest Galilean satellite of Jupiter *3.476 Mm – Diameter of Earth's Moon *3.643 Mm – Diameter of Io (moon), Io, a moon of Jupiter *4.821 Mm – Diameter of Callisto (moon), Callisto, a moon of Jupiter *4.879 Mm – Diameter of Mercury (planet), Mercury *5.150 Mm – Diameter of Titan (moon), Titan, the largest moon of Saturn *5.262 Mm – Diameter of Jupiter's moon Ganymede (moon), Ganymede, the largest moon in the Solar System *6.371 Mm – Earth radius, Radius of Earth *6.792 Mm – Diameter of Mars


10 megametres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths starting at 107
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (#10 megametre, 10 megametres or 10,000 kilometres).


Conversions

10 megametres (10 Mm) is *6,215 miles *side of a
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
of area 100,000,000 square kilometres (km2) *radius of a
circle A circle is a shape consisting of all points in a plane that are at a given distance from a given point, the centre. Equivalently, it is the curve traced out by a point that moves in a plane so that its distance from a given point is con ...
of area 314,159,265 km2


Human-defined scales and structures

*11.085 Mm – Length of the Kyiv-Vladivostok railway, a longer variant of the Trans-Siberian railway *13.300 Mm – Length of roads rehabilitated and widened under the National Highway Development Project (launched in 1998) in India *39.000 Mm – Length of the SEA-ME-WE 3 optical submarine telecommunications cable, joining 39 points between Norden, Lower Saxony, Norden, Germany and Okinawa, Japan *67.000 Mm – Total length of National highways of India, National Highways in India *80.000 Mm – 20,000 (metric, French) league (unit), leagues (see Jules Verne, ''Twenty Thousand Leagues Under the Sea'')


Geographical

*10 Mm – Approximate altitude of the outer boundary of the exosphere *10.001 Mm – Length of the meridian arc from the North Pole to the Equator (the original definition of the
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
was based on this length) *60.000 Mm – Total length of the mid-ocean ridges


Astronomical

*12.000 Mm – Diameter of Sirius, Sirius B, a
white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...
*12.104 Mm – Diameter of Venus *12.742 Mm – Diameter of Earth *12.900 Mm – Minimum distance of the meteoroid from the centre of Earth on 31 March 2004, closest on record *14.000 Mm – Smallest diameter of Jupiter's Great Red Spot *19.000 Mm – Separation between Pluto and Charon (moon), Charon *30.8568 Mm – 1 nanoparsec *34.770 Mm – Minimum distance of the asteroid
99942 Apophis 99942 Apophis is a near-Earth asteroid and potentially hazardous asteroid with a diameter of that caused a brief period of concern in December 2004 when initial observations indicated a probability up to 2.7% that it would hit Earth on April&nb ...
on 13 April 2029 from the centre of Earth *35.786 Mm – Altitude of geostationary orbit *40.005 Mm – Polar circumference of the Earth *40.077 Mm – Equatorial circumference of the Earth *49.528 Mm – Diameter of Neptune *51.118 Mm – Diameter of Uranus


100 megametres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists lengths starting at 108
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (#100 megametre, 100 megametres or 100,000 kilometres or 62,150 miles). *102 Mm – Diameter of HD 149026 b, an unusually dense gas giant, Jovian planet *115 Mm – Width of Saturn's Rings *120 Mm – Diameter of EBLM J0555-57Ab, the smallest-known star *120 Mm – Diameter of Saturn *142 Mm – Diameter of Jupiter, the largest planet in the Solar System *170 Mm – Diameter of TRAPPIST-1, a star recently discovered to have seven planets around it *174 Mm – Diameter of OGLE-TR-122b *180 Mm – Average distance covered during life *196 Mm – Diameter of Proxima Centauri, a typical red dwarf *257 Mm – Diameter of TrES-4 b *272 Mm – Diameter of WASP-12b *299.792 Mm – One light-second; the distance light travels in vacuum in one second (see speed of light) *300 Mm – Diameter of WASP-79b *314 Mm – Diameter of CT Cha b *384.4 Mm (238,855 mi) – Average Lunar distance (astronomy), Earth-Moon distance *671 Mm – Separation between Jupiter and Europa (moon), Europa *428 Mm – Diameter of GQ Lupi b, one of the list of largest exoplanets, largest-known planets *986 Mm – Diameter of HD 100546 b's surrounding disk


1 gigametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to  
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (109 m). To help compare different distances this section lists lengths starting at 109
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (1 gigametre (Gm) or 1 billion
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s). *1.2 Gm – Separation between Saturn and Titan (moon), Titan *1.39 Gm – Diameter of Sun *1.5 Gm – ''(proposed) Expected orbit from Earth of the James Webb Space Telescope'' *2.19 Gm – Closest approach of Comet Lexell to Earth, happened on 1 July 1770; closest comet approach on record *3 Gm – Total length of "wiring" in the human brain *4.2 Gm – Diameter of Algol B *5.0 Gm – Closest approach of Comet Halley to Earth, happened on 10 April 837 *5.0 Gm – ''(proposed) Size of the arms of the giant triangle shaped Michelson interferometer of the Laser Interferometer Space Antenna (LISA) planned to start observations sometime in the 2030s.'' *7.9 Gm – Diameter of Bellatrix, Gamma Orionis *9.0 Gm – Estimated diameter of the event horizon of Sagittarius A*, the supermassive black hole in the center of the Milky Way galaxy


10 gigametres

To help compare different distances this section lists lengths starting at 1010
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (10 1 gigametre, gigametres (Gm) or 10 million kilometres, or 0.07 astronomical units). *15 Gm – Closest distance of Comet Hyakutake from Earth *18 Gm – One light-minute (see yellow sphere in right-hand diagram) *24 Gm – Radius of a heliostationary orbit *30.8568 Gm – 1 microparsec *46 Gm – Apsis, Perihelion distance of Mercury (planet), Mercury (yellow ellipse on the right) *55 Gm – 60,000-year perigee of Mars (last achieved on 27 August 2003) *55 Gm – Radius of Rigel, a blue supergiant star (largest star on right) *58 Gm – Average passing distance between Earth and Mars at the moment they overtake each other in their orbits *61 Gm They derived an angular diameter of 20.58±0.03 milliarcsec, which given a distance of 65 light-years yields a diameter of 61 million km. – Diameter of Aldebaran, an red giant, orange giant star (large star on right) *70 Gm – Apsis, Aphelion distance of Mercury *76 Gm – Neso (moon), Neso's apsis, apocentric distance; greatest distance of a natural satellite from its parent planet (Neptune)


100 gigametres

To help compare distances at different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
this section lists lengths starting at 1011
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (100 Orders of magnitude (length)#1 gigametre, gigametre or 100 million kilometres or 0.7 astronomical units). *109 Gm (0.7 au) Distance between Venus and the Sun *149.6 Gm (93.0 million mi; 1.0 au) – Distance between the Earth and the Sun – the original definition of the astronomical unit *180 Gm (1.2 au) – Maximum diameter of Sagittarius A*, the supermassive black hole in the center of Milky Way galaxy *228 Gm (1.5 au) – Distance between Mars and the Sun *570 Gm (3.8 au) – Length of the tail of Comet Hyakutake measured by ''Ulysses (spacecraft), Ulysses''; the actual value could be much higher *591 Gm (4.0 au) – Minimum distance between the Earth and Jupiter *780 Gm (5.2 au) – Distance between Jupiter and the Sun *947 Gm (6.4 au) – Diameter of Antares, Antares A *965 Gm (6.4 au) – Maximum distance between the Earth and Jupiter


1 terametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to  
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s (1012 m). To help compare different distances, this section lists lengths starting at 1012 m (1 #1 terametre, Tm or 1 billion kilometre, km or 6.7 astronomical units). *1.079 Tm – 7.2 au – One light-hour *1.4 Tm – 9.5 au – Distance between Saturn and the Sun *1.5 Tm – 10 au – Estimated diameter of VV Cephei A, a red supergiant. *1.83 Tm – 12.2 au – Diameter of HR 5171 A, the largest-known yellow hypergiant star although the latest research suggests it is a red hypergiant with a diameter about 2.1 Tm (14 au) *2 Tm – 13.2 au – Estimated diameter of VY Canis Majoris, one of the list of largest stars, largest-known stars *2.9 Tm – 19.4 au – Distance between Uranus and the Sun *4.4 Tm – 29.4 au – Apsis, Perihelion distance of Pluto *4.5 Tm – 30.1 au – Distance between Neptune and the Sun *4.5 Tm – 30.1 au – Inner radius of the Kuiper belt *5.7 Tm – 38.1 au – Perihelion distance of 136199 Eris, Eris *7.3 Tm – 48.8 au – Apsis, Aphelion distance of Pluto *7.5 Tm – 50.1 au – Outer radius of the Kuiper Belt


10 terametres

To help compare different distances this section lists lengths starting at 1013 m (10 #1 terametre, Tm or 10 billion kilometre, km or 67 astronomical units). *10 Tm – 67 AU – Diameter of a hypothetical quasi-star *11.1 Tm – 74.2 AU – Distance that ''Voyager 1'' began detecting returning particles from termination shock *11.4 Tm – 76.2 AU – Apsis, Perihelion distance of 90377 Sedna *12.1 Tm – 70 to 90 AU – Distance to termination shock (''Voyager 1'' crossed at 94 AU) *12.9 Tm – 86.3 AU – Distance to 90377 Sedna in March 2014 *13.2 Tm – 88.6 AU – Distance to ''Pioneer 11'' in March 2014 *14.1 Tm – 94.3 AU – Estimated radius of the Solar System *14.4 Tm – 96.4 AU – Distance to 136199 Eris, Eris in March 2014 (now near its apsis, aphelion) *15.1 Tm – 101 AU – Distance to Heliosphere#Heliosheath, heliosheath *16.5 Tm – 111 AU – Distance to ''Pioneer 10'' as of March 2014 *16.6 Tm – 111.2 AU – Distance to ''Voyager 2'' as of May 2016 *20.0 Tm – 135 AU – Distance to ''Voyager 1'' as of May 2016 *20.6 Tm – 138 AU – Distance to ''Voyager 1'' as of late February 2017 *21.1 Tm – 141 AU – Distance to ''Voyager 1'' as of November 2017 *25.9 Tm – 173 AU – One light-day *30.8568 Tm – 1 miliparsec *55.7 Tm – 371 AU – Aphelion distance of the comet Hale-Bopp


100 terametres

To help compare different distances this section lists lengths starting at 1014 m (100 #1 terametre, Tm or 100 billion kilometre, km or 670 astronomical units). *140 Tm – 937 AU – Apsis, Aphelion distance of 90377 Sedna *172 Tm – 1150 AU – Schwarzschild radius, Schwarzschild diameter of H1821+643, one of the most massive black holes known *181 Tm – 1210 AU – One light-week *757 Tm – 5059 AU – radius of the Stingray Nebula *777 Tm – 5180 AU – One light-month


1 petametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to 1015 
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s. To help compare different distances this section lists lengths starting at 1015 m (1 Pm or 1 trillion kilometre, km or 6685 astronomical units (AU) or 0.11 light-years). *1.0 Pm = 0.105702341 light-years *1.9 Pm ± 0.5 Pm = 12,000 AU = 0.2 light-year radius of Cat's Eye Nebula's inner coreradius = distance times sin(angular diameter/2) = 0.2 light-year. Distance = 3.3 ± 0.9 light-year, kly; angular diameter = 20 arcseconds *4.7 Pm = 30,000 AU = half-light-year diameter of Bok globule Barnard 68 *7.5 Pm – 50,000 AU – Possible outer boundary of Oort cloud (other estimates are 75,000 to 125,000 or even 189,000 Astronomical unit, AU (1.18, 2, and 3 light-years, respectively)) *9.5 Pm – 63,241.1 AU – One light-year, the distance traveled by light in one year *9.9 Pm – 66,000 AU – Apsis, Aphelion distance of the C/1999 F1 (Catalina)


10 petametres

To help compare different distances this section lists lengths starting at 1016 m (10 #1 petametre, Pm or 66,800 astronomical unit, AU, 1.06 light-years). *15 Pm – 1.59 light-years – Possible outer radius of Oort cloud *20 Pm – 2.11 light-years – maximum extent of influence of the Sun's gravitational field *30.9 Pm – 3.26 light-years – 1
parsec The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (au), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, an ...
*39.9 Pm – 4.22 light-years – Distance to Proxima Centauri (nearest star to Sun) *81.3 Pm – 8.59 light-years – Distance to Sirius


100 petametres

To help compare different distances this section lists lengths between 1017 m (100 #1 petametre, Pm or 11 light-years) and 1018 m (106 light-years). *110 Pm – 12 light-years – Distance to Tau Ceti *230 Pm – 24 light-years – Diameter of the Orion Nebula *240 Pm – 25 light-years – Distance to Vega *260 Pm – 27 light-years – Distance to Beta Canum Venaticorum, Chara, a star approximately as bright as our Sun. Its faintness gives us an idea how our Sun would appear when viewed from even so close a distance as this. *350 Pm – 37 light-years – Distance to Arcturus *373.1 Pm – 39.44 light-years – Distance to TRAPPIST-1, a star recently discovered to have 7 planets around it *400 Pm – 42 light-years – Distance to Capella (star), Capella *620 Pm – 65 light-years – Distance to Aldebaran *750 Pm – 79.36 light-years – Distance to Regulus *900 Pm – 92.73 light-years – Distance to Algol


1 exametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to 1018
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s. To help compare different distances this section lists lengths between 1018  m (1 exametre, Em or 105.7 light-years) and 1019 m (10 Em or 1,057 light-years). *1.2 Em – 129 light-years – Diameter of Messier 13 (a typical globular cluster) *1.6 Em – 172 ± 12.5 light-years – Diameter of Omega Centauri (one of the largest-known globular clusters, perhaps containing over a million stars) *3.1 Em – 310 light-years – Distance to Canopus (star), Canopus according to ''Hipparcos''Vizier catalog entry
/ref> * *6.1 Em – 640 light-years – Distance to Betelgeuse according to ''Hipparcos'' *6.2 Em – 650 light-years – Distance to the Helix Nebula, located in the constellation Aquarius (constellation), Aquarius *7.3 Em – 730 light-years – Distance to Rigel according to ''Hipparcos''


10 exametres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 10 exametre, Em (1019 m or 1,100 light-years). *10.6 Em – 1,120 light-years – Distance to WASP-96b *13 Em – 1,300 light-years – Distance to the Orion Nebula *14 Em – 1,500 light-years – Approximate thickness of the Galactic plane, plane of the Milky Way galaxy at the Sun's location *14.2 Em – 1,520 light-years – Diameter of the NGC 604 *30.8568 Em – 3,261.6 light-years – 1 parsec, kiloparsec *31 Em – 3,200 light-years – Distance to Deneb according to ''Hipparcos'' *46 Em – 4,900 light-years – Distance to OGLE-TR-56, the first extrasolar planet discovered using the extrasolar planet#Transit method, transit method *47 Em – 5,000 light-years – Distance to the Boomerang nebula, coldest place known (1 E0 K, 1 K) *53 Em – 5,600 light-years – Distance to the globular cluster Messier 4, M4 and the extrasolar planet PSR B1620-26 b within it *61 Em – 6,500 light-years – Distance to Perseus Spiral Arm (next spiral arm out in the Milky Way galaxy) *71 Em – 7,500 light-years – Distance to Eta Carinae


100 exametres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 100 exametre, Em (1020 m or 11,000 light-years). *150 Em – 16,000 light-years – Diameter of the Small Magellanic Cloud, a dwarf galaxy orbiting the Milky Way *200 Em – 21,500 light-years – Distance to OGLE-2005-BLG-390Lb, the most distant and the most Earth-like planet known *240 Em – 25,000 light-years – Distance to the Canis Major Dwarf Galaxy *260 Em – 28,000 light-years – Distance to the center of the Milky Way, Galaxy *830 Em – 88,000 light-years – Distance to the Sagittarius Dwarf Elliptical Galaxy


1 zettametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to 1021
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s. To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 1 zettametre, Zm (1021  m or 110,000 light-years). *1.7 Zm – 179,000 light-years – Distance to the Large Magellanic Cloud, largest satellite galaxy of the Milky Way *<1.9 Zm – <200,000 light-years – Revised estimated diameter of the disc of the Milky Way, Milky Way Galaxy. The size was previously thought to be half of this. *2.0 Zm – 210,000 light-years – Distance to the Small Magellanic Cloud *2.8 Zm – 300,000 light-years – Distance to the Intergalactic Wanderer, one of the most distant globular clusters of Milky Way *8.5 Zm – 900,000 light-years – Distance to the Leo I Dwarf Galaxy, farthest-known Milky Way satellite galaxy


10 zettametres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 10 zettametre, Zm (1022 m or 1.1 million light-years). *24 Zm – 2.5 million light-years – Distance to the Andromeda Galaxy *30.8568 Zm – 3.2616 million light-years – 1 parsec, megaparsec *40 Zm – 4.2 million light-years – Distance to the IC 10, a distant member of the Local Group of galaxy, galaxies *49.2 Zm – 5.2 million light-years – Width of the Local Group of galaxy, galaxies *95 Zm – 10 million light-years – Distance to the Sculptor Galaxy in the Sculptor Group of galaxies *95 Zm – 10 million light-years – Distance to the Maffei 1, the nearest giant elliptical galaxy in the Maffei 1 group of galaxies, Maffei 1 Group


100 zettametres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 100 zettametre, Zm (1023 m or 11 million light-years). *140 Zm – 15 million light-years – Distance to Centaurus A galaxy *250 Zm – 27 million light-years – Distance to the Pinwheel Galaxy *280 Zm – 30 million light-years – Distance to the Sombrero Galaxy *570 Zm – 60 million light-years – Approximate distance to the Virgo cluster, nearest galaxy cluster *620 Zm – 65 million light-years – Approximate distance to the Fornax cluster *800 Zm – 85 million light-years – Approximate distance to the Eridanus cluster


1 yottametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to 1024 
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s. To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 1 Ym (1024 m or 105.702 million light-years). *1.2 Ym – 127 million light-years – Distance to the closest observed gamma ray burst GRB 980425 *1.3 Ym – 137 million light-years – Distance to the Centaurus Cluster of galaxies, the nearest large supercluster *1.9 Ym – 201 million light-years – Diameter of the Local Supercluster *2.3 Ym – 225 to 250 million light-years – Distance light travels in vacuum in one galactic year *2.8 Ym – 296 million light-years – Distance to the Coma Cluster *3.2 Ym – 338 million light-years – Distance to the Stephan's Quintet *4.7 Ym – 496 million light-years – Length of the Great Wall (astronomy), CfA2 Great Wall, one of the largest observed superstructures in the Universe *6.1 Ym – 645 million light-years – Distance to the Shapley Supercluster *9.5 Ym – 996 million light-years – Diameter of the Eridanus Supervoid


10 yottametres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 10 yottametre, Ym (1025 m or 1.1 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depends on the physical cosmology, cosmological models used. *13 Ym – 1.37 billion light-years – Length of the South Pole Wall *13 Ym – 1.38 billion light-years – Length of the Sloan Great Wall *18 Ym – redshift 0.16 – 1.9 billion light-years – Distance to the quasar 3C 273 (distance measures (cosmology)#Types of distance measures, light travel distance) *30.8568 Ym – 3.2616 billion light-years – 1 gigaparsec *31.2204106 Ym − 3.3 billion light-years − Length of The Giant Arc, a large cosmic structure discovered in 2021 *33 Ym – 3.5 billion light-years – Maximum distance of the 2dF Galaxy Redshift Survey (light travel distance) *37.8 Ym – 4 billion light-years – Length of the Huge-LQG *75 Ym – redshift 0.95 – 8 billion light-years – Approximate distance to the supernova SN 2002dd in the Hubble Deep Field North (light travel distance) *85 Ym – redshift 1.6 – 9 billion light-years – Approximate distance to the gamma-ray burst GRB 990123 (light travel distance) *94.6 Ym – 10 billion light-years – Approximate distance to quasar OQ172 *94.6 Ym – 10 billion light-years – Length of the Hercules–Corona Borealis Great Wall, one of the list of largest cosmic structures, largest and most massive-known cosmic structures known


100 yottametres

To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 100 yottametre, Ym (1026 m or 11 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the physical cosmology, cosmological models used. *124 Ym – redshift 7.54 – 13.1 billion light-years – Distance measures (cosmology)#Types of distance measures, Light travel distance (LTD) to the quasar ULAS J1342+0928, the List of quasars#Most distant quasars, most distant-known quasar as of 2017 *130 Ym – redshift 1,000 – 13.8 billion light-years – Distance (LTD) to the source of the Cosmic microwave background, cosmic microwave background radiation; radius of the observable universe measured as a LTD *260 Ym – 27.4 billion light-years – Diameter of the observable universe (double LTD) *440 Ym – 46 billion light-years – Radius of the universe measured as a comoving distance *590 Ym – 62 billion light-years – Cosmological event horizon: the largest comoving distance from which light will ever reach us (the observer) at any time in the future *886.48 Ym – 93.7 billion light-years – The diameter of the
observable universe The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these ob ...
(twice the particle horizon); however, there might be unobserved distances that are even greater.


1 ronnametre

The ' ( SI symbol: ') is a
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...
of length in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
equal to 1027 
metre The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
s. To help compare different
orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...
, this section lists distances starting at 1 Rm (1027 m or 110 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the physical cosmology, cosmological models used. *>1 Rm - >105.7 billion light-years – Size of universe beyond the observable universe, cosmic light horizon, depending on its curvature; if the curvature is zero (i.e. the universe is spatially flat), the value can be infinity#Infinity in cosmology, infinite (see Shape of the universe) as previously mentioned


See also

*List of examples of lengths *Fermi problem *Scale (analytical tool) *Spatial scale


Notes


References


External links


How Big Are Things?
– displays orders of magnitude in successively larger rooms.

– Travel across the Universe.

(Digital Nature Agency).
Scale of the universe
– interactive guide to length magnitudes *
Orders of Magnitude
(March 2020). {{Portal bar, Physics, Mathematics, Astronomy, Stars, Spaceflight, Outer space, Solar System, Science Orders of magnitude (length), Length Orders of magnitude, Length Lists by length