Gallon pints. These pints are divided into two cups (though the imperial cup is rarely used now), which in turn are divided into two gills (gills are also rarely used). Thus a gallon is equal to four quarts, eight pints, sixteen cups or thirty-two gills. The imperial gill is further divided into five fluid ounces, whereas the US gill is divided into four fluid ounces. Thus an imperial fluid ounce is of an imperial pint or of an imperial gallon, while a US fluid ounce is of a US pint or of a US gallon. The imperial gallon, quart, pint, cup
Gallon one time defined as the volume of a cylinder 6 inches deep and 7 inches in diameter, i.e. . It had been redefined during the reign of Queen Anne, in 1706, as 231 cubic inches exactly, which is the result of the earlier definition with π approximated to . Although the wine gallon had been used for centuries for import duty purposes there was no legal standard of it in the Exchequer and a smaller gallon was actually in use, so this statute became necessary. It remains the US definition today. In 1824, Britain adopted a close approximation to the