2783: How ‘Handle’ and ‘Fifth’ Became Metric Aug 3, 2024

There are certain measurements in imperial or US customary units that are only used in specific contexts, like knots (1 nautical mile per hour), while some others are only used in certain contexts by habit. A ‘fifth’ is a common measurement for alcoholic drinks, its name coming from being a ⅕ of a gallon, and likewise a ‘handle’ is ½ a gallon or in other words 2 quarts. These are now officially defined, even in the US that does not use the metric system, as 750mL (instead of ~757mL) and 1.75L respectively. This makes a fifth and a handle metric terms, even though they are not SI units.