The quart (symbol: qt) 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. 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 The term comes from the Latin (meaning one-quarter) via the French . However, although the French word has the same root, it frequently means something entirely different. In Canadian French in particular, the quart is called , while the pint is called .
History
Since gallons of various sizes have historically been in use, the corresponding quarts have also existed with various sizes.
Definitions and equivalencies
Imperial quart The imperial quart is equal to one-quarter of an imperial gallon of exactly , i.e. . In the United Kingdom, goods may be sold by the quart if the equivalent metric measure is also given. 1 imperial quart ≡imperial gallon≡2imperial pints≡8imperial gills≡40imperial fluid ounces≡liters ≈69.354858cubic inches≈US gallons≈1.20095US liquid quarts≈2.4019US liquid pints≈9.6076US gills≈38.4304US fluid ounces≈US dry quarts≈US dry pints
In Canadian French, by federal law, the imperial quart is called .
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 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 ."Authorized tables" , United States Code, Title 15, ch. 6, subchapter I, sec. 205, accessed 19 July 2008. 1 US liquid quart ≡US gallon≡2US liquid pints≡4US cups≡8US gills≡32US fluid ounces≡litersGuide for the Use of the International System of Units (SI) —US government publicationThis has been the exact conversion since the 1964 redefinition of the liter and the 1959 redefinition of the inch.≡57.75 cubic inchesOne US gallon is defined as exactly 231 cubic inches.≈imperial gallons≈imperial quarts≈imperial pints≈imperial gills≈imperial fluid ounces≡US dry quart≡1US dry pints
US dry quart In the United States, the dry quart is equal to of a US bushel of exactly 2150.42 cubic inches, i.e. 67.200625 cubic inches or . 1 US dry quart ≡US bushel≡US peck≡2US dry pints≡liters≡cubic inches≡US gallon≡1US liquid quarts≡2US liquid pints≡9US gills≡37US fluid ounces≈imperial gallons≈imperial quarts≈imperial pints≈imperial gills≈imperial fluid ounces
Winchester quart The Winchester quart is an obsolescent measure:Trading Standards – Weights and Measures of the City of Winchester it was originally equal to two imperial quarts (half of an imperial gallon) or exactly , but was later metricated to (2.2 imperial quarts). Despite its name, it is unrelated to the Winchester measure.
The 2.5L 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 The reputed quart was a measure equal to two-thirds of an imperial quart (or one-sixth of an imperial gallon), i.e. exactly 0.757681 liters: this is only 0.08% larger than one US fifth (exactly 0.7570823568 liters).
The reputed quart was previously recognized as the standard size of wine bottle in the United Kingdom, and is only about 1% larger than the current standard wine bottle of 0.75L.
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