Quart


The quart 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 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 wikt:quartus via the French wikt:quart#French. 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, while the pint is called chopine.

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.
In Canadian French, by federal law, the imperial quart is called Pint#Other pints.

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.

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.

Winchester quart

The Winchester quart is an obsolescent measure: it was originally equal to two imperial quarts or exactly, but was later metricated to . 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, i.e. exactly 0.757681 liters: this is only 0.08% larger than one US fifth.
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.