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Quart

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Quart
One-quart milk jugs (top shelf); half-gallon (two-quart) milk jugs (bottom shelf)
General information
Unit ofVolume
Symbolqt
Conversions (imperial)
1 imp qt in ...... is equal to ...
   SI-compatible units   1.1365225 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   0.946352946 L
   Imperial units   0.8326742 imp qt
   Imperial units   57.75 in3
   US dry quarts   92400/107521 dry qt

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 size of a quart has varied with the different values of gallons over time, and in the case of the dry quart, in reference to different commodities.

Name

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The 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

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Since gallons of various sizes have historically been in use, the corresponding quarts have also existed with various sizes.

Definitions and equivalencies

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Imperial quart

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The imperial quart is equal to one-quarter of an imperial gallon of exactly 4.54609 L, i.e. 1.1365225 L. In the United Kingdom, goods may be sold by the quart if the equivalent metric measure is also given.[3]

1 imperial quart  14 imperial gallon
2 imperial pints
8 imperial gills
40 imperial fluid ounces
1.1365225 liters[4][a]
69.35486 cubic inches
0.3002375 US gallons
1.20095 US liquid quarts
2.4019 US liquid pints
9.6076 US gills
38.4304 US fluid ounces
1.0320567 US dry quarts
2.0641135 US dry pints

In Canadian French, by federal law, the imperial quart is called pinte.[5][2]

US liquid quart

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In 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 0.9144 meters: from this definition the metric equivalents for inches, feet, miles, area measures, and measures of volume are determined. The US liquid quart is equal to one-quarter of a gallon of exactly 231 cubic inches, i.e. 57.75 cubic inches or 0.946352946 L.[6][7]

1 US liquid quart  14 US gallon
2 US liquid pints
4 US cups
8 US gills
32 US fluid ounces
0.946352946 liters[7][8]
57.75 cubic inches[9]
0.2081685 imperial gallons
0.8326742 imperial quarts
1.6653484 imperial pints
6.6613935 imperial gills
33.3069674 imperial fluid ounces
92400/107521 US dry quart
177279/107521 US dry pints

US dry quart

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In the United States, the dry quart is equal to 1/32 of a US bushel of exactly 2150.42 cubic inches, i.e. 67.200625 cubic inches or 1.101220942715 L.

1 US dry quart  1/32 US bushel
2 US dry pints
1.101220942715 liters[7][8]
67.200625 cubic inches
107521/369600 US gallon
115121/92400 US liquid quarts
215121/46200 US liquid pints
93571/11550 US gills
371367/5775 US fluid ounces
0.2422347 imperial gallons
0.968939 imperial quarts
1.9378779 imperial pints
7.7515118 imperial gills
38.7575589 imperial fluid ounces

Winchester quart

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The Winchester quart is an obsolescent measure:[10] it was originally equal to two imperial quarts (half of an imperial gallon) or exactly 2.273045 L, but was later metricated to 2.5 L (2.2 imperial quarts). Despite its name, it is unrelated to the Winchester measure.[11]

The 2.5 L bottles in which laboratory chemicals are supplied are sometimes referred to as Winchester quart bottles, although these contain 10% more than a traditional Winchester quart.

Reputed quart

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The reputed quart was a measure equal to two-thirds of an imperial quart (one-sixth of an imperial gallon), or exactly 0.7576816 liters, which is only 0.08% larger than one US fifth (exactly 0.7570823568 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.[12][13]

Notes

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  1. ^ This has been the exact conversion since the redefinition of the imperial gallon in 1976 in the UK,[4] and in 1964 in Canada.

References

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  1. ^ BS350:Part 1:1974 Conversion factors and tables Part 1. Basis of tables. Conversion factors. British Standards Institution. 1974. pp. 10, 86.
  2. ^ a b c "Mesures Canada". Archived from the original on 20 January 2018. Retrieved 1 October 2012.
  3. ^ "Weights and Measures Act 1985, Section 8". Government of the United Kingdom. Archived from the original on 18 November 2019. Retrieved 15 November 2019.
  4. ^ 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.
  5. ^ "Measurement Canada". Archived from the original on 10 August 2017. Retrieved 1 October 2012.
  6. ^ "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.
  7. ^ 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
  8. ^ a b This has been the exact conversion since the 1964 redefinition of the liter and the 1959 redefinition of the inch.
  9. ^ One US gallon is defined as exactly 231 cubic inches.
  10. ^ Trading Standards – Weights and Measures of the City of Winchester Archived 22 January 2009 at the Wayback Machine
  11. ^ "Units: W". www.ibiblio.org. Retrieved 18 February 2025.
  12. ^ "Reputed, adj. (b)". Oxford English Dictionary. Archived from the original on 24 September 2015. Retrieved 24 December 2014.
  13. ^ "Reputed quart". Sizes – The Online Quantinary. Archived from the original on 26 September 2015. Retrieved 24 December 2014.
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  • The dictionary definition of quart at Wiktionary
  • Media related to Quart at Wikimedia Commons