Pint a limited extent in Commonwealth nations. In the United States, two pints are used: a liquid pint (≈ 473 ml) and a less-common dry pint (≈ 551 ml). Each of these pints is one-eighth of its respective gallon, but the gallons differ. This difference dates back to 1824, when the British Weights and Measures Act standardised various liquid measures throughout the British Empire, while the United States continued to use the earlier English measure. The imperial pint consists of 20 imperial fluid ounces and the US liquid pint is 16 US fluid ounces, making the imperial fluid ounce about 4%
Imperial and US customary measurement systems gallon and pint continued to be used in the retail trade for the sale of loose goods or goods measured or weighed in front of the customer. Since 1 January 2000 it has been unlawful to use imperial units for weights and measures in retail trade in the United Kingdom except as supplementary units or for the sale of draught beer and cider by the pint or milk that is sold in returnable containers. When colonies attained dominion status, they also attained the right to control their own systems of weights and measures. Many adopted the imperial system of units