Pints & British Imperial Volume Units
The British Imperial pint is defined as 1/8th of an Imperial gallon (defined in 1824 as the volume of 10 pounds of distilled water weighed in air with brass weights at a barometer reading 30 inches of mercury at a temperature of 62 °F). The latest redefinition, in 1984, of the Imperial gallon makes it exactly 4.54609 litres. Thus the Imperial pint is exactly 0.56826125 litres.
Although officially abolished in the United Kingdom and British Commonwealth countries, the Imperial pint is still in day to day use for the sale of milk and beer. Almost all other liquids are sold by metric measures in shops and supermarkets, although pubs and bars may still sell soft drinks in pints and half pints.
Table of British Imperial Volume Units
The following table gives Imperial volume units with their equivalent size in litres and US gallons.
|Unit||Abbreviation||As Litres||As UK Gallons||As US Gallons||Notes|
|fluid ounce||fl oz||0.0284131||0.00625||0.0075059||Often used in British recipes|
|gill||gi||0.1420653||0.03125||0.0375297||Spirits were sold in one sixth of a gill in England and one fifth of a gill in Scotland|
|pint||pt||0.56826125||0.125||0.15011875||Beer and milk that is delivered are still sold in pints in the UK|
|quart||qt||1.1365225||0.25||0.3002375||The quart is as expected ¼ of a gallon|
1 Imperial gallon = 4 quarts = 8 pints = 32 gills = 160 fluid ounces
History & Background
The current British Imperial liquid volume measures have their foundations in the Weights and Measures Act of 1824, when the Imperial gallon was defined. This unit was close to the Ale gallon - one of many different gallons in use at the time. Note that the US Customary gallon was based on the Wine gallon in use at the time of US Independence.
Various minor tweaks to the size of the gallon have taken place since the 1824 Act, with the latest definition in the The Weights and Measures Act of 1985 being in terms of SI metric litres.
Conversion Formulae for British Imperial Pints
To Metric - Litres
- 1 Imperial pint = 0.56826125 litres
- 1 litre = 1.75975399 Imperial pints
To US Customary - Pints
- 1 Imperial pint = 1.200949926 US pints
- 1 US pint = 0.832674185 Imperial pints