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.
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]
Since gallons of various sizes have historically been in use, the corresponding quarts have also existed with various sizes.
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 | ≡ | 1⁄4 | imperial gallon |
≡ | 2 | imperial pints | |
≡ | 8 | imperial gills | |
≡ | 40 | imperial fluid ounces | |
≡ | 1.1365225 | liters [4] [a] | |
≈ | 69.35486 | cubic inches | |
≈ | 38.4304 | US fluid ounces |
In Canadian French, by federal law, the imperial quart is called pinte . [5] [2]
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 | ≡ | 1⁄4 | US liquid gallons |
≡ | 2 | US liquid pints | |
≡ | 4 | US liquid cups | |
≡ | 8 | US liquid gills | |
≡ | 32 | US fluid ounces | |
≡ | 0.946352946 | liters [7] [8] | |
≡ | 57.75 | cubic inches [9] | |
≈ | 33.30697 | imperial fluid ounces |
In the United States, the dry quart is equal to one-quarter of a US dry gallon of exactly 268.8025 cubic inches, i.e. 67.200625 cubic inches or 1.101220942715 L.
1 US dry quart | = | 1⁄32 | US bushel |
= | 1⁄8 | US peck | |
= | 1⁄4 | US dry gallon | |
= | 2 | US dry pints | |
≡ | 1.101220942715 | liters [7] [8] | |
= | 67.200625 | cubic inches | |
≡ | 115121/92400 | US liquid quarts | |
≈ | 38.757558 | imperial fluid ounces | |
≡ | 37 1367/5775 | US fluid ounces |
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.
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]