Koku (Rice Measurement)

Koku (written 石) is a Japanese unit of weight used for measuring rice. Historically the Koku was a highly important unit of measurement used to estimate the yield of rice on a piece of land, which in turn was used to calculate salaries amongst the land-owning classes. 1 Koku was said to be the amount of rice necessary to feed one person for a year (approximately 150kg). 

Different variations of the measurement exist for shipping, timber, and fish. In older English-language texts the unit is sometimes romanized as "Kokf." Koku as a unit of volume is explored in the "Koku (Volume)" constant page.