The
quart is a
unit of
volume (for either the
imperial or
United States customary units) equal to a quarter of a
gallon (hence the name
quart), two
pints, or four
cups. Since gallons of various sizes have historically been in use, quarts of various sizes have also existed; see
gallon for further discussion. Three of these kinds of quarts remain in current use, all approximately equal to one
litre. Its proper abbreviation is
qt.