Gallon Gallon The gallon () is a unit of measurement for volume and fluid capacity in both the US customary units and the British imperial systems of measurement. Three significantly different sizes are in current use: the imperial gallon defined as litres (4 imperial quarts or 8 imperial pints), which is used in the United Kingdom, Canada, and some Caribbean nations; the US gallon defined as 231 cubic inches (4 US liquid quarts or 8 US liquid pints) or about , which is used in the US and some Latin American and Caribbean countries; and the least-used US dry gallon defined
Wine gallon Wine gallon A wine gallon is a unit of capacity that was used routinely in England as far back as the 14th century, and by statute under Queen Anne since 1707. Britain abandoned the wine gallon in 1826 when it adopted imperial units for measurement. The 1707 wine gallon is the basis of the United States' gallon, as well as other measures. The English and U.S. gallon are not the same volume, because of different basis for the pressure and temperature at which the volume is calculated. In England, the volume was measured at and barometric pressure of , which