Quart Explained

Quart
Quantity:Volume
Symbol:qt
Units Imp1:SI-compatible units
Inunits Imp1:1sigfig=6NaNsigfig=6
Units Imp2:US customary units
Inunits Imp2:≈1sigfig=7NaNsigfig=7
Units Imp3:US customary units
Inunits Imp3:≈1sigfig=7NaNsigfig=7
Units Us1:SI-compatible units
Inunits Us1:≈1sigfig=7NaNsigfig=7
Units Us2:Imperial units
Inunits Us2:≈1sigfig=7NaNsigfig=7
Units Us3:Imperial units
Inunits Us3:1sigfig=4NaNsigfig=4
Units Us4:US dry gallon
Inunits Us4:≈1sigfig=6NaNsigfig=6

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 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

The term comes from the Latin Latin: [[wikt:quartus|quartus]] (meaning one-quarter) via the French French: [[wikt:quart#French|quart]]. However, although the French word French: [[:fr:quart (unité)|quart]] has the same root, it frequently means something entirely different. In Canadian French in particular, the quart is called French: [[:fr:pinte|pinte]], whilst the pint is called French: [[:fr:chopine|chopine]].

History

See main article: Gallon. Since gallons of various sizes have historically been in use, the corresponding quarts have also existed with various sizes.

Definitions and equivalencies

US liquid quart

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 .[2]

1 US liquid quart =US liquid gallons
=2US liquid pints
=4US liquid cups
=8US liquid gills
=32US fluid ounces
=57.75cubic inches[3]
liters[4] [5]
33.307imperial fluid ounces

US dry quart

In the United States, the dry quart is equal to one quarter of a US dry gallon, or exactly .

1 US dry quart =US bushels
=US pecks
=US dry gallons
=2US dry pints
=cubic inches
liters
38.758imperial fluid ounces

Imperial quart

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.[6]

1 imperial quart =imperial gallons
=2imperial pints
=40imperial fluid ounces
liters
69.355cubic inches
38.430US fluid ounces
In Canadian French, by federal law, the imperial quart is called French: [[Pint#Other pints|pinte]].[7] [8]

Winchester quart

The Winchester quart is an archaic measure,[9] roughly equal to 2 imperial quarts or 2.25 liters. The 2.5L 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

The reputed quart was a measure equal to two-thirds of an imperial quart (or one-sixth of an imperial gallon), at about 0.7577liters, 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 0.75L.[10] [11]

Notes and References

  1. Book: BS350:Part 1:1974 Conversion factors and tables Part 1. Basis of tables. Conversion factors . 1974 . British Standards Institution . 10, 86.
  2. https://www.law.cornell.edu/uscode/text/15/205- "Authorized tables"
  3. One US liquid gallon is defined as 231 cubic inches.
  4. http://physics.nist.gov/cuu/pdf/sp811.pdf Guide for the Use of the International System of Units (SI)
  5. This has been the exact conversion since the 1964 redefinition of the liter and the 1959 redefinition of the inch.
  6. Web site: Weights and Measures Act 1985, Section 8. Government of the United Kingdom. 15 November 2019. 18 November 2019. https://web.archive.org/web/20191118022519/http://www.legislation.gov.uk/ukpga/1985/72/section/8. live.
  7. Web site: Measurement Canada . 1 October 2012 . 10 August 2017 . https://web.archive.org/web/20170810172405/http://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/Home . live .
  8. Web site: Mesures Canada . 1 October 2012 . 20 January 2018 . https://web.archive.org/web/20180120070033/http://www.ic.gc.ca/eic/site/mc-mc.nsf/fra/accueil . live .
  9. http://www.hants.gov.uk/regulatory/tradingstandards/wmhistory.html Trading Standards – Weights and Measures of the City of Winchester
  10. Book: Oxford English Dictionary. 24 December 2014. Reputed, adj. (b). 24 September 2015. https://web.archive.org/web/20150924085514/http://www.oed.com/view/Entry/163235?redirectedFrom=reputed+quart#eid25894027. live.
  11. Web site: Reputed quart. Sizes – The Online Quantinary. 24 December 2014. 26 September 2015. https://web.archive.org/web/20150926141342/http://sizes.com/units/quart_reputed.htm. live.