Pint (pt)

The pint is a mid-size measure for drinks and dairy: beer, milk, cream and ice cream. In both the US and British systems, 8 pints make a gallon, but the gallons differ, so the pints do too.

When Britain created its imperial measures in 1824, the new pint came out larger than the old wine-gallon pint that the US kept (NIST Handbook 44, Appendix B). The US also keeps a dry pint for dry goods measured by volume, and it is larger than the US liquid pint (NIST Handbook 44, Appendix C).

In the UK, most goods must be sold in metric units, but the law keeps the pint for two uses: draught beer and cider, and milk in returnable containers (Weights and Measures Act 1985, section 8). That is why a British pub still pours beer by the pint.

Anywhere else in UK trade, a pint figure can appear only next to the metric amount. Bottled and canned drinks are therefore labeled in milliliters.

In the US, the old saying "a pint's a pound the world around" is close for water: a US pint of water weighs about 1.04 pounds. The saying does not travel well, because an imperial pint of water weighs about 1.25 pounds.

It also fails for most other foods. Based on USDA data, a pint of whole milk weighs about 1.08 pounds, while a pint of all-purpose flour weighs only about 0.55 pounds.