The quart (symbol: qt)[1] is a unit of volume equal to a quarter of a gallon.

Historically, the exact size of the quart has varied with the different values of gallons over time and in reference to different commodities.

In the United Kingdom, goods may be sold by the quart if the equivalent metric measure is also given.

[3] 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 exactly equal to 0.9144 meters: from this definition the metric equivalents for inches, feet, miles, area measures, and measures of volume are determined.