The gallon (/ˈɡælən/) is a unit of measurement for liquid capacity
in both the US customary units and the British imperial systems of
measurement. Three significantly different sizes are in current use:
the imperial gallon defined as 7000454609000000000♠4.54609 litres (8
imperial pints), which is used in the United Kingdom, Canada, and some
1.1 English system gallons 1.2 Imperial gallon 1.3 US liquid gallon 1.4 US dry gallon
2 Worldwide usage of gallons 3 Relationship to other units 4 History 5 References 6 External links
Definitions The gallon currently has one definition in the imperial system, and two definitions (liquid and dry) in the US customary system. Historically, there were many definitions and redefinitions. English system gallons There were more than a few systems of liquid measurements in the pre-1884 United Kingdom.
Winchester or Corn
Henry VII (Winchester) corn gallon from 1497 onwards was 154.80 fl oz Elizabeth I corn gallon from 1601 onwards was 155.70 fl oz William III corn gallon from 1697 onwards was 156.90 fl oz
Old English (Elizabethan) Ale
London 'Guildhall' gallon (before 1688) was 129.19 fl oz Jersey gallon (from 1562 onwards) was 139.20 fl oz Guernsey gallon (17th century origins till 1917) was 150.14 fl oz
A Shell petrol station selling 2* and 4* (leaded petrol) by the gallon in the UK. C. Mid-Late 1990s
The imperial (UK) gallon, now defined as exactly 7000454609000000000♠4.54609 litres (about 277.42 cubic inches), is used in some Commonwealth countries and was originally based on the volume of 10 pounds (approximately 4.54 kg) of water at 62 °F (17 °C). The imperial fluid ounce is defined as 1/160 of an imperial gallon; there are four quarts in a gallon, two pints in a quart, and 20 Imperial fluid ounces in an imperial pint. US liquid gallon
A fuel station in the United States displaying fuel prices per US gallon
The US gallon is legally defined as 231 cubic inches, which is exactly 3.785411784 litres. A US liquid gallon of water weighs about 8.34 pounds or 3.78 kilograms at 62 °F (17 °C), making it about 16.6% lighter than the imperial gallon. There are four quarts in a gallon, two pints in a quart and 16 US fluid ounces in a US pint, which makes the US fluid ounce equal to 1/128 of a US gallon. In order to overcome the effects of expansion and contraction with temperature when using a gallon to specify a quantity of material for purposes of trade, it is common to define the temperature at which the material will occupy the specified volume. For example, the volume of petroleum products and alcoholic beverages are both referenced to 60 °F (16 °C) in government regulations. US dry gallon Main article: Dry gallon This dry measure is one-eighth of a US Winchester bushel of 7003215042000000000♠2150.42 cubic inches; it is therefore equal to exactly 268.8025 cubic inches or about 6997440500000000000♠4.405 L. The US dry gallon is not used in commerce, and is not listed in the relevant statute, which jumps from the dry quart to the peck. Worldwide usage of gallons
Typical units of gasoline in each country. Litre US gallon Imperial gallon No data
Gallons used in fuel economy expression in Canada and the United
Kingdom are Imperial gallons.
Despite its status as a U.S. territory, and unlike American Samoa,
the Northern Mariana Islands, Guam, and the U.S. Virgin
Islands, Puerto Rico ceased selling gasoline by the US gallon in
The gallon was removed from the list of legally defined primary units
of measure catalogued in the EU directive 80/181/EEC for trading and
official purposes, with effect from 31 December 1994. Under the
directive the gallon could still be used – but only as a
supplementary or secondary unit. One of the effects of this
directive was that the United Kingdom amended its own legislation to
replace the gallon with the litre as a primary unit of measure in
trade and in the conduct of public business, effective from 30
Ireland also passed legislation in response to the EU directive, with
the effective date being 31 December 1993. Though the gallon has
ceased to be the legally defined primary unit, it can still be legally
used in both the UK and Ireland as a supplementary unit.
The United Arab Emirates started selling gasoline by the litre in
2010, along with Guyana, and Panama in 2013. The two
former had used the Imperial gallon and the latter the US gallon until
The corn gallon, or Winchester gallon, of about 268.8 cubic inches (≈ 4.405 L), The wine gallon, or Queen Anne's gallon, which was 231 cubic inches (≈ 3.79 L), and The ale gallon of 282 cubic inches (≈ 4.62 L).
The corn or dry gallon was used in the United States until recently
for grain and other dry commodities. It is one-eighth of the
(Winchester) bushel, originally a cylindrical measure of 18 1/2
inches in diameter and 8 inches in depth. That made the dry
gallon (9 1/4)2 × π cubic inches ≈
6997440488409860128♠268.80252 in3. The bushel, which like dry
quart and pint still sees some use, was later defined to be
2150.42 cubic inches exactly, making its gallon exactly
(6997440488377086000♠4.40488377086 L). In previous centuries,
there had been a corn gallon of around 271 to 272 cubic inches.
The wine, fluid, or liquid gallon has been the standard US gallon
since the early 19th century. The wine gallon, which some sources
relate to the volume occupied by eight medieval merchant pounds of
wine, was at one time defined as the volume of a cylinder 6 inches
deep and 7 inches in diameter, i.e. 6 in × (3 1/2 in)2
× π ≈ 230.907 06 cubic inches. It had been redefined during
the reign of Queen Anne, in 1706, as 231 cubic inches exactly, which
is the result of the earlier definition with π approximated to 22/7.
Although the wine gallon had been used for centuries for import duty
purposes there was no legal standard of it in the
Comparison of historic gallons
Volume Definition Inverted volume (gallons per cubic foot) Approx. weight of water (pounds per gallon @ 62 °F) Cylindrical approximation
(cu in) (L or dm3) Diameter (in) Height (in) Relative error (%)
216 (Roman unciae) ≈ 7000353960000000000♠3.5396 Roman congius 8 7.8 5 11 0.01
preserved at the
231 7000378541178400000♠3.785411784 statute of 5th of Queen Anne (UK wine gallon, standard US gallon) 7.48 8.33 7 6 0.04
264.8 ≈ 4.3393 ancient Rumford quart (1228) 6.53 9.57 7.5 6 0.1
266.25 ≈ 4.3631 ancient Rumford (1228)
268.8025 7000440488377086000♠4.40488377086 Winchester, statute 13 + 14 by William III (corn gallon, old US dry gallon) 6.43 9.71 18.5 1 6995100000000000000♠0.00001
272 ≈ 4.4573 corn gallon (1688)
277.18 ≈ 4.5422 statute 12 of Anne (coal gallon) = 33/32 corn gallons 6.23 10
≈7002277419433000000♠277.419433 7000454609000000000♠4.54609 standard imperial gallon (metric) (1964 Canada gallon, 1985 UK gallon) 6.23 10 5⅔ 11 0.000 2
≈7002277419555000000♠277.419555 7000454609200000000♠4.546092 Imperial gallon (1895) Re-determined in 1895, as defined in 1963. 6.23 10
282 ≈ 4.6212 Treasury (beer and ale gallon) 6.13 10.2
^ IEEE Std 260.1-2014
^ Ricketts, Carl. "CAPACITY MEASURES OF THE BRITISH ISLES" (PDF).
Retrieved 6 September 2016.
^ "NIST Handbook 44 - 2012 Edition Appendix C "General Tables of Units
of Measurement"". p. C-5.
^ Uniform Laws and Regulations in the areas of legal metrology and
engine fuel quality (PDF). US Department of Commerce, National
Institute of Standards and Technology. 2011. pp. 9–13,
^ State of New Hampshire Dept of Weights and Measure Archived 13 April
2012 at the Wayback Machine.
^ 27 CFR section 5.21
^ Authorized tables, US Code, Title 15, ch. 6, subchapter I, sec. 205,
accessed 19 July 2008.
^ "Archived copy". Archived from the original on 5 January 2013.
Retrieved 6 November 2012.
^ Statutory Instrument 2001/3523 Environmental Protection - The
Passenger Car (Fuel Consumption and CO2 Emissions Information)
Regulations 2001 (PDF). The Stationery Office. 30 October 2001.
ISBN 0-11-038743-0. Retrieved 1 December 2011.
^ "Gasoline goes up eleven cents per gallon tomorrow". Samoa News.
Archived from the original on 4 March 2016.
^ "Archived copy". Archived from the original on 30 October 2006.
Retrieved 30 September 2013.
^ "UPDATE: Gas prices down 10 cents to $4.73 for a gallon of
unleaded". Pacific Daily News. Archived from the original on
^ JOY BLACKBURN (16 July 2012). "7-cent-per-gallon WAPA tax goes into
effect". Virgin Islands Daily News. Archived from the original on 30
^ Pesquera de Busquets, Carmen T; Barcelo, Carlos Romero (14 June
1979). "Order to establish the price of half (1/2) galon [sic] of
gasoline as transitory measure and that the litter [sic] should be the
final metric measurement for the sale of gasoline in Puerto Rico"
(PDF). San Juan, Puerto Rico: Departamento de Asuntos del Consumidor.
Retrieved 21 May 2013.
^ The Council of the European Communities (9 February 2000). "Council
Directive 80/181/EEC of 20 December 1979 on the approximation of the
laws of the Member States relating to Unit of measurement and on the
repeal of Directive 71/354/EEC". Retrieved 7 February 2009. The legal
units of measurement ... for economic, public health, public safety or
administrative purposes ... litre
^ "The Units of Measurement Regulations 1995 (Article 4)". 13 July
1995. Retrieved 1 December 2011.
^ "Units of Measurement Directive". LACORS. 1995. Archived from the
original on 24 April 2012. Retrieved 26 November 2011.
^ "Guidance Note on the use of Metric Units of Measurement by the
Public Sector" (PDF). Department of Trade and Industry. 1995. Archived
from the original (PDF) on 7 February 2011. Retrieved 20 March
^ "S.I. No. 255/1992 — European Communities (Units of Measurement)
Regulations, 1992." Irish Statute Book. Office of the Attorney
General. 9 September 1992. Retrieved 1 December 2011.
^ Badih, Samia (30 December 2009). "Petrol stations in UAE go the
metric route". Gulf News. Retrieved 11 September 2012.
^ "Gas prices at Guyoil stations remain below $1,000 mark". Caribbean
Millers Association. 20 April 2011. Archived from the original on 28
June 2013. Retrieved 20 May 2013.
^ "Liters replace gallons at pump as Panama goes metric". Newsroom,
Panama. 20 April 2013. Archived from the original on 25 May 2013.
Retrieved 20 May 2013.
^ a b "International Fuel Prices 2010/11 - 7th Edition" (PDF). GTZ
Transport Policy Advisory Services on behalf of the [German] Federal
Ministry for Economic Cooperation and Development. p. 100.
Retrieved 16 January 2012.
^ "Petrol Prices March 2014 in Yangon, Myanmar".
Find more aboutGallonat's sister projects
Definitions from Wiktionary Media from Wikimedia Commons Travel guide from Wikivoyage Data from Wikidata
v t e
Systems of measurement
International System of Units
Apothecaries' Avoirdupois Troy Astronomical Electrical Temperature
atomic geometrized Gaussian Lorentz–Heaviside Planck quantum chromodynamical Stoney
Overview Introduction Outline History Metrication
Overview Comparison Foot–pound–second (FPS)
meter–kilogram–second (MKS) meter–tonne–second (MTS) centimeter–gram–second (CGS) gravitational quadrant–eleventh-gram–second (QES) (hebdometre–undecimogramme–second (HUS))
Byzantine Cornish Cypriot Czech Danish Dutch English Estonian Finnish French (Trad. • Mesures usuelles) German Greek Hungary Icelandic Irish Scottish Italian Latvia Luxembourgian Maltese Norwegian Ottoman Polish Portuguese Romanian Russian Serbian Slovak Spanish Swedish Switzerland Welsh Winchester measure
Afghan Cambodian Chinese Hindu Hong Kong India Indonesian Japanese Korean Mongolian Omani Philippine Pegu Singaporean Sri Lankan Syrian Taiwanese Tatar Thai Vietnamese
Algerian Ethiopian Egyptian Eritrean Guinean Libyan Malagasy Mauritian Moroccan Seychellois Somalian South African Tunisian Tanzanian
Costa Rican Cuban Haitian Honduran Mexico Nicaraguan Puerto Rican
Argentine Brazilian Chilean Colombian Paraguayan Peruvian Uruguayan Venezuelan
Arabic Biblical and Talmudic Egyptian Greek Hindu Indian Mesopotamian Persian Roman
Humorous (FFF system) Obsolete Unusual