units of measurement
A unit of measurement is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a mul ...
and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of
science
Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earli ...
and
commerce
Commerce is the large-scale organized system of activities, functions, procedures and institutions directly and indirectly related to the exchange (buying and selling) of goods and services among two or more parties within local, regional, natio ...
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 Intern ...
French Revolution
The French Revolution ( ) was a period of radical political and societal change in France that began with the Estates General of 1789 and ended with the formation of the French Consulate in November 1799. Many of its ideas are conside ...
gave rise to 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 Intern ...
, and this has spread around the world, replacing most customary units of measure. In most systems,
length
Length is a measure of distance. In the International System of Quantities, length is a quantity with dimension distance. In most systems of measurement a base unit for length is chosen, from which all other units are derived. In the Inte ...
(distance),
mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different element ...
, and
time
Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, t ...
are ''base quantities''.
Later science developments showed that an electromagnetic quantity such as
electric charge
Electric charge is the physical property of matter that causes charged matter to experience a force when placed in an electromagnetic field. Electric charge can be ''positive'' or ''negative'' (commonly carried by protons and electrons respecti ...
or electric current could be added to extend the set of base quantities.
Gaussian units
Gaussian units constitute a metric system of physical units. This system is the most common of the several electromagnetic unit systems based on cgs (centimetre–gram–second) units. It is also called the Gaussian unit system, Gaussian-cgs uni ...
have only length, mass, and time as base quantities, with no separate electromagnetic dimension. Other quantities, such as power and
speed
In everyday use and in kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity ...
, are derived from the base set: for example, speed is distance per unit time. Historically a wide range of units was used for the same type of quantity: in different contexts, length was measured in
inch
Measuring tape with inches
The inch (symbol: in or ″) is a unit of length in the British imperial and the United States customary systems of measurement. It is equal to yard or of a foot. Derived from the Roman uncia ("twelft ...
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 ...
chains
A chain is a wikt:series#Noun, serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression (physics), compression but line (g ...
,
furlong
A furlong is a measure of distance in imperial units and United States customary units equal to one eighth of a mile, equivalent to 660 feet, 220 yards, 40 rods, 10 chains or approximately 201 metres. It is now mostly confined to use i ...
s,
mile
The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 Engli ...
s,
nautical mile
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today t ...
s, stadia, leagues, with conversion factors that were not powers of ten.
The preference for a more universal and consistent system only gradually spread with the growth of international trade and science. Changing a measurement system has costs in the near term, which results in resistance to such a change. The substantial benefit of conversion to a more rational and internationally consistent system of measurement has been recognized and promoted by scientists, engineers and politicians, and has resulted in most of the world adopting a commonly agreed metric system.
In antiquity, ''systems of measurement'' were defined locally: the different units might be defined independently according to the length of a king's thumb or the size of his foot, the length of stride, the length of arm, or maybe the weight of water in a keg of specific size, perhaps itself defined in ''hands'' and ''knuckles''. The unifying characteristic is that there was some definition based on some standard. Eventually ''
cubit
The cubit is an ancient unit of length based on the distance from the elbow to the tip of the middle finger. It was primarily associated with the Sumerians, Egyptians, and Israelites. The term ''cubit'' is found in the Bible regarding ...
s'' and '' strides'' gave way to "customary units" to meet the needs of merchants and scientists.
In the metric system and other recent systems, underlying relationships between quantities, as expressed by formulae of physics such as
Newton's laws of motion
Newton's laws of motion are three basic laws of classical mechanics that describe the relationship between the motion of an object and the forces acting on it. These laws can be paraphrased as follows:
# A body remains at rest, or in moti ...
, is used to select a small number of base quantities for which a unit is defined for each, from which all other units may be derived. Secondary units (multiples and submultiples) are derived from these base and derived units by multiplying by powers of ten, so for example where the unit of length is 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 p ...
; a distance of 1 m is 1,000 millimetres, or 0.001 kilometres.
Current practice
Metrication is complete or nearly complete in almost all countries. US customary units are heavily used in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
and to some degree in
Liberia
Liberia (), officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to its northwest, Guinea to its north, Ivory Coast to its east, and the Atlantic Ocean to its south and southwest. It ...
Burma
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...
. U.S. units are used in limited contexts in Canada due to the large volume of trade; there is also considerable use of imperial weights and measures, despite ''de jure'' Canadian conversion to metric.
A number of other jurisdictions have laws mandating or permitting other systems of measurement in some or all contexts, such as the United Kingdom – whose road signage legislation, for instance, only allows distance signs displaying
imperial units
The imperial system of units, imperial system or imperial units (also known as British Imperial or Exchequer Standards of 1826) is the system of units first defined in the British Weights and Measures Act 1824 and continued to be developed th ...
(miles or yards) – or Hong Kong.HK Weights and Measures Ordinance /ref>
In the United States, metric units are used almost universally in science, widely in the military, and partially in industry, but customary units predominate in household use. At retail stores, the litre (spelled 'liter' in the U.S.) is a commonly used unit for volume, especially on bottles of beverages, and milligrams, rather than grains, are used for medications. Some other non- SI units are still in international use, such as
nautical mile
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today t ...
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 Intern ...
s of units have evolved since the adoption of the first well-defined system in France in 1795. During this evolution the use of these systems has spread throughout the world, first to non-English-speaking countries, and then to English speaking countries.
Multiples and submultiples of metric units are related by powers of ten and their names are formed with
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''. Particula ...
. This relationship is compatible with the decimal system of numbers and it contributes greatly to the convenience of metric units.
In the early metric system there were two base units, 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 p ...
for length and the
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 ...
for mass. The other units of length and mass, and all units of area, volume, and derived units such as density were derived from these two base units.
Mesures usuelles (
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with Franc ...
for ''customary measurements'') were a system of measurement introduced as a compromise between the metric system and traditional measurements. It was used in France from 1812 to 1839.
A number of variations on the metric system have been in use. These include
gravitational systems
''Gravitational Systems'' is an album by American jazz pianist Matthew Shipp featuring a duo with violinist Mat Maneri, which was recorded in 1998 and released on the Swiss hatOLOGY label. Shipp played previously with Maneri on the albums ''Critic ...
metre–kilogram–second system
The MKS system of units is a physical system of measurement that uses the metre, kilogram, and second (MKS) as base units. It forms the base of the International System of Units (SI), though SI has since been redefined by different fundamental co ...
(mks). In some engineering fields, like computer-aided design, millimetre–gram–second (mmgs) is also used.
The current international standard for the metric system is the International System of Units ( or SI). It is a system in which all units can be expressed in terms of seven units. The units that serves as the
SI base unit
The SI base units are the standard units of measurement defined by the International System of Units (SI) for the seven base quantities of what is now known as the International System of Quantities: they are notably a basic set from which all ...
s are 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 p ...
,
kilogram
The kilogram (also kilogramme) is the unit of mass in the International System of Units (SI), having the unit symbol kg. It is a widely used measure in science, engineering and commerce worldwide, and is often simply called a kilo colloquially ...
ampere
The ampere (, ; symbol: A), often Clipping (morphology), shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One amp ...
,
kelvin
The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and ph ...
candela
The candela ( or ; symbol: cd) is the unit of luminous intensity in the International System of Units (SI). It measures luminous power per unit solid angle emitted by a light source in a particular direction. Luminous intensity is analogous t ...
.
Imperial and US customary units
Both
imperial unit
The imperial system of units, imperial system or imperial units (also known as British Imperial or Exchequer Standards of 1826) is the system of units first defined in the British Weights and Measures Act 1824 and continued to be developed th ...
British Empire
The British Empire was composed of the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading post ...
and the
British Commonwealth
The Commonwealth of Nations, simply referred to as the Commonwealth, is a political association of 56 member states, the vast majority of which are former territories of the British Empire. The chief institutions of the organisation are the C ...
, but in all these countries they have been largely supplanted by the metric system. They are still used for some applications in the United Kingdom but have been mostly replaced by the metric system in commercial,
scientific
Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earliest archeological evidence ...
, and industrial applications. US customary units, however, are still the main system of measurement in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
. While some steps towards
metrication
Metrication or metrification is the act or process of converting to the metric system of measurement. All over the world, countries have transitioned from local and traditional units of measurement to the metric system. This process began in F ...
have been made (mainly in the late 1960s and early 1970s), the customary units have a strong hold due to the vast industrial infrastructure and commercial development.
While imperial and US customary systems are closely related, there are a number of differences between them. Units of length and area (the
inch
Measuring tape with inches
The inch (symbol: in or ″) is a unit of length in the British imperial and the United States customary systems of measurement. It is equal to yard or of a foot. Derived from the Roman uncia ("twelft ...
,
foot
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 mad ...
,
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 0 ...
,
mile
The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 Engli ...
, etc.) have been identical since the adoption of the
International Yard and Pound Agreement
The international yard and pound are two units of measurement that were the subject of an agreement among representatives of six nations signed on 1 July 1959: the United States, United Kingdom, Canada, Australia, New Zealand, and South Africa. ...
; however, America and, formerly, India retained older definitions for surveying purposes. This gave rise to the US survey foot for instance. The avoirdupois units of mass and weight differ for units larger than a
pound
Pound or Pounds may refer to:
Units
* Pound (currency), a unit of currency
* Pound sterling, the official currency of the United Kingdom
* Pound (mass), a unit of mass
* Pound (force), a unit of force
* Rail pound, in rail profile
Symbols
* Po ...
(lb). The imperial system uses a stone of 14 lb, a long
hundredweight
The hundredweight (abbreviation: cwt), formerly also known as the centum weight or quintal, is a British imperial and US customary unit of weight or mass. Its value differs between the US and British imperial systems. The two values are distin ...
of 112 lb and a long ton of 2240 lb. The stone is not used in the US and the hundredweights and tons are short: 100 lb and 2000 lb respectively.
Where these systems most notably differ is in their units of volume. A US
fluid ounce
A fluid ounce (abbreviated fl oz, fl. oz. or oz. fl., old forms ℥, fl ℥, f℥, ƒ ℥) is a unit of volume (also called ''capacity'') typically used for measuring liquids. The British Imperial, the United States customary, and the United ...
(fl oz), about 29.6 millilitres (ml), is slightly larger than the imperial fluid ounce (about 28.4 ml). However, as there are 16 US fl oz to a US
pint
The pint (, ; symbol pt, sometimes abbreviated as ''p'') is a unit of volume or capacity in both the imperial and United States customary measurement systems. In both of those systems it is traditionally one eighth of a gallon. The British imp ...
and 20 imp fl oz per imperial pint, the imperial pint is about 20% larger. The same is true of
quart
The quart (symbol: qt) is an English unit of volume equal to a quarter gallon. Three kinds of quarts are currently used: the liquid quart and dry quart of the US customary system and the of the British imperial system. All are roughly e ...
s,
gallon
The gallon is a unit of volume in imperial units and United States customary units. Three different versions are in current use:
*the imperial gallon (imp gal), defined as , which is or was used in the United Kingdom, Ireland, Canada, Aus ...
s, etc.; six US gallons are a little less than five imperial gallons.
The avoirdupois system served as the general system of mass and weight. In addition to this there are the
troy
Troy ( el, Τροία and Latin: Troia, Hittite: 𒋫𒊒𒄿𒊭 ''Truwiša'') or Ilion ( el, Ίλιον and Latin: Ilium, Hittite: 𒃾𒇻𒊭 ''Wiluša'') was an ancient city located at Hisarlik in present-day Turkey, south-west of Çan ...
and the
apothecaries' system
The apothecaries' system, or apothecaries' weights and measures, is a historical system of mass and volume units that were used by physicians and apothecaries for medical prescriptions and also sometimes by scientists."Medicinal-Gewicht, Apothek ...
s. Troy weight was customarily used for
precious metal
Precious metals are rare, naturally occurring metallic chemical elements of high economic value.
Chemically, the precious metals tend to be less reactive than most elements (see noble metal). They are usually ductile and have a high lu ...
s,
black powder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate ( saltpeter) ...
and gemstones. The troy ounce is the only unit of the system in current use; it is used for precious metals. Although the troy ounce is larger than its avoirdupois equivalent, the pound is smaller. The obsolete troy pound was divided into 12 ounces, rather than the 16 ounces per pound of the avoirdupois system. The apothecaries' system was traditionally used in
pharmacology
Pharmacology is a branch of medicine, biology and pharmaceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous (from within the body) molecule which exerts a biochemi ...
, but has now been replaced by the metric system; it shared the same pound and ounce as the troy system but with different further subdivisions.
Natural units
Natural units
In physics, natural units are physical units of measurement in which only universal physical constants are used as defining constants, such that each of these constants acts as a coherent unit of a quantity. For example, the elementary charge ...
are
units of measurement
A unit of measurement is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a mul ...
defined in terms of universal physical constants in such a manner that selected physical constants take on the numerical value of one when expressed in terms of those units. Natural units are so named because their definition relies on only properties of
nature
Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans ar ...
and not on any human construct. Varying systems of natural units are possible, depending on the choice of constants used.
Some examples are as follows:
* Geometrized unit systems are useful in relativistic physics. In these systems,
speed of light
The speed of light in vacuum, commonly denoted , is a universal physical constant that is important in many areas of physics. The speed of light is exactly equal to ). According to the special theory of relativity, is the upper limit fo ...
reduced Planck constant
The Planck constant, or Planck's constant, is a fundamental physical constant of foundational importance in quantum mechanics. The constant gives the relationship between the energy of a photon and its frequency, and by the mass-energy equivalen ...
is included in the list of defining constants. It is based on only properties of
free space
A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or " void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often di ...
rather than of any object or particle.
*
Stoney units In physics the Stoney units form a system of units named after the Irish physicist George Johnstone Stoney, who first proposed them in 1881. They are the earliest example of natural units, i.e., a coherent set of units of measurement designed so th ...
is a system of geometrized units in which the Coulomb constant and the
elementary charge
The elementary charge, usually denoted by is the electric charge carried by a single proton or, equivalently, the magnitude of the negative electric charge carried by a single electron, which has charge −1 . This elementary charge is a funda ...
atomic physics
Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. Atomic physics typically refers to the study of atomic structure and the interaction between atoms. It is primarily concerned wit ...
, particularly for describing the properties of
electron
The electron (, or in nuclear reactions) 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 partic ...
s. The atomic units have been chosen to use several constants relating to the electron: the electron mass, the
elementary charge
The elementary charge, usually denoted by is the electric charge carried by a single proton or, equivalently, the magnitude of the negative electric charge carried by a single electron, which has charge −1 . This elementary charge is a funda ...
reduced Planck constant
The Planck constant, or Planck's constant, is a fundamental physical constant of foundational importance in quantum mechanics. The constant gives the relationship between the energy of a photon and its frequency, and by the mass-energy equivalen ...
. The unit of
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...
in this system is the total energy of the
electron
The electron (, or in nuclear reactions) 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 partic ...
* The American football field, which has a playing area long by wide. This is often used by the American public media for the sizes of large buildings or parks. It is used both as a unit of length (, the length of the playing field excluding goal areas) and as a unit of area (), about .
* British media also frequently uses the
football pitch
A football pitch (also known as soccer field) is the playing surface for the game of association football. Its dimensions and markings are defined by Law 1 of the Laws of the Game, "The Field of Play". The pitch is typically made of natural t ...
for equivalent purposes, although soccer pitches are not of a fixed size, but instead can vary within defined limits ( long, and wide, giving an area of ). However the
UEFA Champions League
The UEFA Champions League (abbreviated as UCL, or sometimes, UEFA CL) is an annual club football competition organised by the Union of European Football Associations (UEFA) and contested by top-division European clubs, deciding the competi ...
field must be exactly giving an area of or . For example, " HSS vessels are aluminium catamarans about the size of a football pitch."
* Larger areas are also expressed as a multiple of the areas of certain American states, or subdivisions of the UK etc.
Energy
* A ton of
TNT equivalent
TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a ...
, and its multiples the kiloton, the megaton, and the gigaton. Often used in stating the power of very energetic events such as
explosion
An explosion is a rapid expansion in volume associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Supersonic explosions created by high explosives are kno ...
s and
volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates ...
asteroid
An asteroid is a minor planet of the Solar System#Inner solar system, inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic o ...
impacts. A
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 ...
of TNT as a unit of
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...
books
A book is a medium for recording information in the form of writing or images, typically composed of many pages (made of papyrus, parchment, vellum, or paper) bound together and protected by a cover. The technical term for this physica ...
as a unit of energy. (Its yield was roughly 13 kilotons, or 60 TJ.)
* One stick of dynamite.
Units of currency
A unit of measurement that applies to
money
Money is any item or verifiable record that is generally accepted as payment for goods and services and repayment of debts, such as taxes, in a particular country or socio-economic context. The primary functions which distinguish money ar ...
is called a
unit of account
In economics, unit of account is one of the money functions. A unit of account is a standard numerical monetary unit of measurement of the market value of goods, services, and other transactions. Also known as a "measure" or "standard" of rela ...
in economics and unit of measure in accounting. This is normally a
currency
A currency, "in circulation", from la, currens, -entis, literally meaning "running" or "traversing" is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes and coins.
A more general ...
issued by a
country
A country is a distinct part of the world, such as a state, nation, or other political entity. It may be a sovereign state or make up one part of a larger state. For example, the country of Japan is an independent, sovereign state, whil ...
or a fraction thereof; for instance, the
US dollar
The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...
and US cent ( of a dollar), or the
euro
The euro (symbol: €; code: EUR) is the official currency of 19 out of the member states of the European Union (EU). This group of states is known as the eurozone or, officially, the euro area, and includes about 340 million citizens . ...
and euro cent.
ISO 4217
ISO 4217 is a standard published by the International Organization for Standardization (ISO) that defines alpha codes and numeric codes for the representation of currencies and provides information about the relationships between individual ...
is the international standard describing three letter codes (also known as the currency code) to define the names of currencies established by the International Organization for Standardization (ISO).
Historical systems of measurement
Throughout history, many official systems of measurement have been used. While no longer in official use, some of these customary systems are occasionally used in day-to-day life, for instance in
cooking
Cooking, cookery, or culinary arts is the art, science and craft of using heat to prepare food for consumption. Cooking techniques and ingredients vary widely, from grilling food over an open fire to using electric stoves, to baking in vari ...
Ethiopian
Ethiopians are the native inhabitants of Ethiopia, as well as the global diaspora of Ethiopia. Ethiopians constitute several component ethnic groups, many of which are closely related to ethnic groups in neighboring Eritrea and other parts of ...
Libyan
Demographics of Libya is the demography of Libya, specifically covering population density, ethnicity, education level, health of the populace, economic status, and religious affiliations, as well as other aspects of the Libyan population. The ...
Mauritian
Mauritians (singular Mauritian; french: Mauricien; Creole: ''Morisien'') are nationals or natives of the Republic of Mauritius and their descendants. Mauritius is a multi-ethnic society, with notable groups of people of South Asian (notably ...
South African __NOTOC__
South African may relate to:
* The nation of South Africa
* South African Airways
* South African English
* South African people
* Languages of South Africa
* Southern Africa
Southern Africa is the southernmost subregion of the Afric ...
*
Tanzanian
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...
Asia
*
Arabic
Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walte ...
M. Ismail Marcinkowski, ''Measures and Weights in the Islamic World. An English Translation of Professor Walther Hinz's Handbook "Islamische Maße und Gewichte"'', with a foreword by Professor Bosworth, F.B.A. Kuala Lumpur, ISTAC, 2002, . This work is an annotated translation of a work in German by the late German orientalist Walther Hinz, published in the ''Handbuch der Orientalistik'', erste Abteilung, Ergänzungsband I, Heft 1, Leiden, The Netherlands: E. J. Brill, 1970.
* Afgan
* Cambodian
* Chinese
*
Hebrew
Hebrew (; ; ) is a Northwest Semitic language of the Afroasiatic language family. Historically, it is one of the spoken languages of the Israelites and their longest-surviving descendants, the Jews and Samaritans. It was largely preserved ...
(
Biblical
The Bible (from Koine Greek , , 'the books') is a collection of religious texts or scriptures that are held to be sacred in Christianity, Judaism, Samaritanism, and many other religions. The Bible is an anthologya compilation of texts of a ...
and
Talmud
The Talmud (; he, , Talmūḏ) is the central text of Rabbinic Judaism and the primary source of Jewish religious law ('' halakha'') and Jewish theology. Until the advent of modernity, in nearly all Jewish communities, the Talmud was the cen ...
Indonesian
Indonesian is anything of, from, or related to Indonesia, an archipelagic country in Southeast Asia. It may refer to:
* Indonesians, citizens of Indonesia
** Native Indonesians, diverse groups of local inhabitants of the archipelago
** Indonesia ...
Korean
Korean may refer to:
People and culture
* Koreans, ethnic group originating in the Korean Peninsula
* Korean cuisine
* Korean culture
* Korean language
**Korean alphabet, known as Hangul or Chosŏn'gŭl
**Korean dialects and the Jeju language
** ...
Philippine
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
*
Mesopotamian
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the ...
Singaporean
Singaporeans, or the Singaporean people, refers to citizens or people who identify with the sovereign island city-state of Singapore. Singapore is a multi-ethnic, multi-cultural and multi-lingual country. Singaporeans of Chinese, Malay, I ...
Syrian
Syrians ( ar, سُورِيُّون, ''Sūriyyīn'') are an Eastern Mediterranean ethnic group indigenous to the Levant. They share common Levantine Semitic roots. The cultural and linguistic heritage of the Syrian people is a blend of both indig ...
Myanmar
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...
Europe
*
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
Byzantine
The Byzantine Empire, also referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire primarily in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantin ...
Cypriot
Cypriot (in older sources often "Cypriote") refers to someone or something of, from, or related to the country of Cyprus.
* Cypriot people, or of Cypriot descent; this includes:
** Armenian Cypriots
** Greek Cypriots
** Maronite Cypriots
** Tur ...
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with Franc ...
(now)
*
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with Franc ...
(to 1795)
*
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
*
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
*
Hungary
Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croa ...
Maltese
Maltese may refer to:
* Someone or something of, from, or related to Malta
* Maltese alphabet
* Maltese cuisine
* Maltese culture
* Maltese language, the Semitic language spoken by Maltese people
* Maltese people, people from Malta or of Malte ...
Scottish
Scottish usually refers to something of, from, or related to Scotland, including:
*Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland
*Scottish English
*Scottish national identity, the Scottish ide ...
*
Serbian
Serbian may refer to:
* someone or something related to Serbia, a country in Southeastern Europe
* someone or something related to the Serbs, a South Slavic people
* Serbian language
* Serbian names
See also
*
*
* Old Serbian (disambiguat ...
Swedish
Swedish or ' may refer to:
Anything from or related to Sweden, a country in Northern Europe. Or, specifically:
* Swedish language, a North Germanic language spoken primarily in Sweden and Finland
** Swedish alphabet, the official alphabet used by ...
Turkish
Turkish may refer to:
*a Turkic language spoken by the Turks
* of or about Turkey
** Turkish language
*** Turkish alphabet
** Turkish people, a Turkic ethnic group and nation
*** Turkish citizen, a citizen of Turkey
*** Turkish communities and mi ...
*
Tatar
The Tatars ()Tatar in the Collins English Dictionary is an umbrella term for different
*
Welsh
Welsh may refer to:
Related to Wales
* Welsh, referring or related to Wales
* Welsh language, a Brittonic Celtic language spoken in Wales
* Welsh people
People
* Welsh (surname)
* Sometimes used as a synonym for the ancient Britons (Celtic peopl ...
Mexico
Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...
Argentine
Argentines (mistakenly translated Argentineans in the past; in Spanish ( masculine) or ( feminine)) are people identified with the country of Argentina. This connection may be residential, legal, historical or cultural. For most Argentines ...
Peruvian
Peruvians ( es, peruanos) are the citizens of Peru. There were Andean and coastal ancient civilizations like Caral, which inhabited what is now Peruvian territory for several millennia before the Spanish conquest in the 16th century; Peruvian p ...
*
Uruguayan
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while borderi ...
Arabic
Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walte ...
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
Mesopotamian
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the ...
ISO 31
ISO 31 ( Quantities and units, International Organization for Standardization, 1992) is a superseded international standard concerning physical quantities, units of measurement, their interrrelationships and their presentation. It was revised a ...
Medieval weights and measures
The following systems arose from earlier systems, and in many cases utilise parts of much older systems. For the most part they were used to varying degrees in the Middle Ages and surrounding time periods. Some of these systems found their way in ...
Petrograd Standard
A standard or standard hundred was a measure of timber used in trade.
The ''standard'' varied in number, size and composition from country to country so the term is usually proceeded by the region or port of origin. The countries of the Balti ...
Weights and measures
A unit of measurement is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a mul ...
Notes and references
Bibliography
* Tavernor, Robert (2007), ''Smoot's Ear: The Measure of Humanity'',