A bushel is a unit of dry volume, usually subdivided into eight local gallons in the systems of Imperial units and U.S. customary units. It is used for volumes of dry commodities, not liquids, most often in agriculture. It is abbreviated as bsh. or bu.
Bushels are now most often used as units of mass rather than of volume. The bushels in which grains are bought and sold on commodity markets or at local grain elevators, and for reports of grain production, are all units of mass. This is done by assigning a standard weight to each commodity that is to be measured in bushels. These bushels depend on the commodities being measured; some of the more common ones are (all exact):
Other specific values are defined (and those definitions may vary in different jurisdictions, including from state to state in the United States) for other grains, oilseeds, fruits, vegetables, coal, hair, and many other commodities.
Government policy in the United States is to phase out units such as the bushel and replace them with the metric system as used for all purposes in the rest of the world, and for all scientific and technical purposes world wide. It is therefore important to know how the bushel relates to the metric equivalent, and whether the bushels are used as units of mass or units of volume.
The name “bushel” has also been used to translate foreign units of a similar size and sometimes shared origin, like the German “Scheffel”.
The bushel was originally a measure of capacity for grain. During the Middle Ages, the bushel of wheat was supposed to weigh 64 tower pounds, but when the tower system was abolished in the 16th century, it was described as 56 avoirdupois pounds. The bushel was rarely used in Scotland, Ireland or Wales during the Middle Ages.
Until and before the 19th century there were even more gallons in use. Examples: 1792 cu in: standard wine gallon preserved at Guildhall 1848 cu in: statute of 5th of Anne 2118.4 cu in: ancient Rumford quart (1228) 2124 cu in: Exchequer (Henry VII, 1091, with rim) 2130 cu in: ancient Rumford (1228) 2150 cu in (approx.): Winchester, statute 13 + 14 by William III. 2168 cu in − 16 spoonfuls: Exchequer (Henry VII., 1601, E.E.) 2168 cu in: Exchequer (1601, E.), corn 2176 cu in: corn (1688) 2217.44 cu in: coal, statute 12 of Anne 2224 cu in: Exchequer (Henry VII, with copper rim) 2227.2 cu in: Exchequer (1601 and 1602 pints) 2240 cu in: Exchequer (1601 quart) 2256 cu in: Treasury (English brewery casks)