Koku

The koku is a traditional Japanese unit of volume historically used to measure dry capacity, particularly rice. Standardized under the Shakukan-ho system in 1891, one koku equals exactly 1,800/11 liters, or approximately 180.39 liters (0.18039 cubic meters). In feudal Japan, the koku served as the fundamental economic benchmark for assessing land yields, tax obligations, and samurai stipends, representing enough rice to feed one person for a year.