The grain (gr) is a unit of mass in the international mass and length units.
Definition of the grain
One grain is equal to 1⁄7000 of a pound.
From the Weights and Measures Act of 1985: PART VI: Measurement of Mass
Value in terms of the SI
One grain is equal to 0.06479891 grams.
Traditionally, the grain was the base unit of the English weight system, a common practice in farming societies. The English grain was the weight of a single seed of barleycorn and therefore larger than other grains on the continent based on wheat.
The smallest bird is the bee hummingbird. With an average weight of 40 grains (2.5 grams), the females are slightly bigger than the males who only weigh 30 grains (2 grams) on average.
|short hundredweight†||cwt||100 pounds|
|long hundredweight*||cwt||4 quarters|
|short ton†||st||20 short hundredweight|
|long ton*||lt||20 long hundredweight|
* specific to the United Kingdom
† specific to the United States of America
The International Mass and Length Units
The International Mass and Length Units are units based on the international yard and the international pound.
They were created in 1959 when Australia, Canada, New Zealand, South Africa, the United Kingdom and the United States of America agreed upon a common definition of the yard and the pound.