Comparison of the imperial and US customary measurement systems adopted a system based on the 231-cubic-inch wine gallon for all fluid purposes. This became the US fluid gallon. Both the imperial and US fluid gallon are divided into 4 quarts, 8 pints or 32 gills. However, whereas the US gill is divided into 4 US fluid ounces, the imperial gill is divided into 5 imperial fluid ounces. So whilst the imperial gallon, quart, pint and gill are about 20% larger than their US fluid measure counterparts, the fluid ounce is about 4% smaller. Note that one avoirdupois ounce of water has an approximate volume of one imperial fluid ounce
Gallon works out at approximately (). The metric definition of exactly cubic decimetres (also after the litre was redefined in 1964, ≈ ) was adopted shortly afterwards in Canada, but from 1976 the conventional value of was used in the United Kingdom until the Canadian convention was adopted in 1985. Historically, gallons of various sizes were used in many parts of Western Europe. In these localities, it has been replaced as the unit of capacity by the litre. Gallon The gallon () is a unit of measurement for volume and fluid capacity in both the US customary units and the British