The quart (symbol: qt)[1] is a unit of volume equal to a quarter of a gallon. Three kinds of quarts are currently used: the liquid quart and dry quart of the US customary system and the imperial quart of the British imperial system. All are roughly equal to one liter. It is divided into two pints or (in the US) four cups. Historically, the exact size of the quart has varied with the different values of gallons over time and in reference to different commodities.
| Quart | |
|---|---|
_(3).jpg) One-quart milk jugs (top shelf); half-gallon (two-quart) milk jugs (bottom shelf) | |
| General information | |
| Unit of | Volume |
| Symbol | qt |
| Conversions (imperial) | |
| 1 imp qt in ... | ... is equal to ... |
| SI-compatible units | 1.13652 L |
| US customary units | ≈ 1.200950 US qt |
| US customary units | ≈ 69.35486 in3 |
| Conversions (US) | |
| 1 US qt in ... | ... is equal to ... |
| SI-compatible units | ≈ 0.9463529 L |
| Imperial units | ≈ 0.8326742 imp qt |
| Imperial units | 57.75 in3 |
| US dry gallon | ≈ 0.859367 US dry qt |
Name
editThe term comes from the Latin quartus (meaning one-quarter) via the French quart. However, although the French word quart has the same root, it frequently means something entirely different. In Canadian French in particular, the quart is called pinte,[2] whilst the pint is called chopine.[2]
History
editSince gallons of various sizes have historically been in use, the corresponding quarts have also existed with various sizes.
Definitions and equivalencies
edit
US liquid quart
editIn the United States, traditional length and volume measures have been legally standardized for commerce by the international yard and pound agreement of 1959, using the definition of 1 yard being exactly equal to 0.9144 meters. From this definition is derived the metric equivalencies for inches, feet, and miles, area measures, and measures of volume. The US liquid quart equals 57.75 cubic inches, which is exactly equal to 0.946352946 L.[3][4]
| 1 US liquid quart | = | 1⁄4 | US liquid gallons |
| = | 2 | US liquid pints | |
| = | 4 | US liquid cups | |
| = | 8 | US liquid gills | |
| = | 32 | US fluid ounces | |
| = | 57.75 | cubic inches[5] | |
| ≡ | 0.946352946 | liters[4][6] | |
| ≈ | 33.307 | imperial fluid ounces |
US dry quart
editIn the United States, the dry quart is equal to one quarter of a US dry gallon, or exactly 1.101220942715 L.
| 1 US dry quart | = | 1⁄32 | US bushels |
| = | 1⁄8 | US pecks | |
| = | 1⁄4 | US dry gallons | |
| = | 2 | US dry pints | |
| = | 67.200625 | cubic inches | |
| ≡ | 1.101 | liters[4][6] | |
| ≈ | 38.758 | imperial fluid ounces |
Imperial quart
editThe imperial quart, which is used for both liquid and dry capacity, is equal to one quarter of an imperial gallon, or exactly 1.1365225 liters. In the United Kingdom goods may be sold by the quart if the equivalent metric measure is also given.[7]
| 1 imperial quart | = | 1⁄4 | imperial gallons |
| = | 2 | imperial pints | |
| = | 40 | imperial fluid ounces | |
| ≡ | 1.1365225 | liters[8][a] | |
| ≈ | 69.355 | cubic inches | |
| ≈ | 38.430 | US fluid ounces |
In Canadian French, by federal law, the imperial quart is called pinte.[9][2]
Winchester quart
editThe Winchester quart is an archaic measure,[10] roughly equal to 2 imperial quarts or 2.25 liters. The 2.5 L bottles in which laboratory chemicals are supplied are sometimes referred to as Winchester quart bottles, although they contain slightly more than a traditional Winchester quart.
Reputed quart
editThe reputed quart was a measure equal to two-thirds of an imperial quart (or one-sixth of an imperial gallon), at about 0.7577 liters, which is very close to one US fifth (0.757 liters).
The reputed quart was previously recognized as a standard size of wine bottle in the United Kingdom, and is only about 1% larger than the current standard wine bottle of 0.75 L.[11][12]
Notes
editReferences
edit- ^ BS350:Part 1:1974 Conversion factors and tables Part 1. Basis of tables. Conversion factors. British Standards Institution. 1974. pp. 10, 86.
- ^ a b c "Mesures Canada". Archived from the original on 20 January 2018. Retrieved 1 October 2012.
- ^ "Authorized tables" Archived 23 August 2020 at the Wayback Machine, United States Code, Title 15, ch. 6, subchapter I, sec. 205, accessed 19 July 2008.
- ^ a b c Guide for the Use of the International System of Units (SI) Archived 3 June 2016 at the Wayback Machine—US government publication
- ^ One US liquid gallon is defined as 231 cubic inches.
- ^ a b This has been the exact conversion since the 1964 redefinition of the liter and the 1959 redefinition of the inch.
- ^ "Weights and Measures Act 1985, Section 8". Government of the United Kingdom. Archived from the original on 18 November 2019. Retrieved 15 November 2019.
- ^ a b Text of the Units of Measurement Regulations 1995 as originally enacted or made within the United Kingdom, from legislation.gov.uk. Retrieved 3 May 2011.
- ^ "Measurement Canada". Archived from the original on 10 August 2017. Retrieved 1 October 2012.
- ^ Trading Standards – Weights and Measures of the City of Winchester Archived 22 January 2009 at the Wayback Machine
- ^ "Reputed, adj. (b)". Oxford English Dictionary. Archived from the original on 24 September 2015. Retrieved 24 December 2014.
- ^ "Reputed quart". Sizes – The Online Quantinary. Archived from the original on 26 September 2015. Retrieved 24 December 2014.
