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
Pint fluid pint of water weighs about a pound (16 ounces), resulting in the popular saying, "A pint's a pound, the world around." However, a US pint of water weighs 1.04375 pounds and the statement does not hold the world around because the imperial (UK) pint, which was also the standard measure in Australia, India, Malaya, New Zealand, South Africa, etc., weighs 1.25 pounds. A different saying for the imperial pint is "a pint of water's a pound and a quarter". The pint is traditionally one-eighth of a gallon. In the Latin of the apothecaries' system, "octavius" or "octarius" (plural "octavii"