Weird Units of Measurement

And Their Word Origins

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Have you ever wondered where some of our weird units of measurement come from? It's interesting to know the history behind some of these terms.


Acre: A unit of measurement equal to 43,560 square feet. It is used primarily to measure land or sea floor area. Originally this indicated as much as a yoke of oxen could plow in one day.

Bale: A bundle used for packaging hay, cotton, or similar material. For cotton, a bale is about 500 pounds.

The origin was probably Dutch, and early use refers to a round bundle wrapped in canvas.

Bolt: A measurement of fabric equal to 50 or 60 yards. This was used in Middle English (1150-1349) to indicate a rolled bundle of cloth.

Carat: Measurement used for the weight of a diamond. One carat is equal to one fifth of a gram. The word comes from the carob bean, whose consistent weight was used in times past to measure gemstones.

Cubit: An ancient unit of measurement equal to about 18 inches. The cubit is supposedly derived from the distance between a Pharaoh's elbow to the farthest fingertip of his extended hand.

Gross: Twelve dozen items or pieces. This measurement derives from the number of matches or boxes produced in 19th Century US factories.

Fathom: A measurement that equals six feet, originally meaning the length between a man's outstretched arms. It is an old Saxon word.

Hogshead: A liquid measurement equal to 63 gallons or a large cask or barrel that holds 63 to 140 gallons.

The name origin is Late Middle English (1350-1469) but the reason is unknown. It possibly refers to the shape of the barrel, which resembles a hog.

Horse power: The word which originated in the early nineteenth century refers to the power needed to lift 550 pounds one foot off the ground in one second.

This is now the common unit for measuring an engine's power.

Karat: The measure of the purity of gold with 24-karat being pure gold. The word origin is the same as carat.

Knot: A unit of speed most often used for measuring the speed of ships. One knot equals approximately 1.15 miles per hour. The origin is based on the practice of observing a knotted log line, or line tied to a floating piece of wood, to measure speed.

League: Approximately 3 nautical miles. Origin is Late Middle English (1350-1469).

Magnum: Used typically for wine, a magnum is a large bottle equaling 1.5 liters. This is the size of two normal bottles. The word origin is Latin, from magnus (large).

Ream: Five hundred sheets of paper. Origin is Arabic, from rizma, a word meaning bundle.

Stone: A unit of measurement used in the United Kingdom, equaling 14 pounds. In Late Middle English (1350-1469) this also referred to a lump of metal used as a standard measure device.

Township: A division of territory in the United States equal to 6 square miles, containing 36 sections or 36 square miles. The word origin is Old English (before 1149), but the current meaning of the word is North American and came into use in the late seventeenth century.

Origins from Shorter Oxford English Dictionary. Fifth Edition. Oxford: Oxford University Press, 2002.