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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   1.13652 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

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.

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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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 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  = 14 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

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In 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  = 132 US bushels
= 18 US pecks
= 14 US dry gallons
= 2 US dry pints
= 67.200625 cubic inches
1.101220942715 liters[4][6]
38.758 imperial fluid ounces

Imperial quart

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The 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  = 14 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

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The 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

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The 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

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  1. ^ This has been the exact conversion since the redefinition of the imperial gallon in 1976 in the UK,[8] 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. ^ "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.
  4. ^ 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
  5. ^ One US liquid gallon is defined as 231 cubic inches.
  6. ^ a b This has been the exact conversion since the 1964 redefinition of the liter and the 1959 redefinition of the inch.
  7. ^ "Weights and Measures Act 1985, Section 8". Government of the United Kingdom. Archived from the original on 18 November 2019. Retrieved 15 November 2019.
  8. ^ 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.
  9. ^ "Measurement Canada". Archived from the original on 10 August 2017. Retrieved 1 October 2012.
  10. ^ Trading Standards – Weights and Measures of the City of Winchester Archived 22 January 2009 at the Wayback Machine
  11. ^ "Reputed, adj. (b)". Oxford English Dictionary. Archived from the original on 24 September 2015. Retrieved 24 December 2014.
  12. ^ "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