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 British Virgin Islands also requires that beer and cider be sold in pints. Also, in Canada, water amounts in air purifiers are advertised in pints as well as BTUs ("British thermal units"), see metrication. In Australia and New Zealand, a subtle change was made to 1 pint milk bottles during the conversion from imperial to metric in the 1970s. The height and diameter of the milk bottle remained unchanged, so that existing equipment for handling and storing the bottles was unaffected, but the shape was adjusted to increase the capacity from 568 ml to 600 ml – a conveniently rounded