- Japanese: 石 (koku)
Koku is a measurement of volume, the equivalent of about 180 liters. In theory, 1 koku of rice (about 150 kilograms) should be enough to feed 1 man for a year. When fiefs were distributed, their wealth was often assessed in the amount of rice (or equivalent goods) that the administrator could expect to receive in taxes, an amount known as kokudaka. This, in turn, would indirectly dictate the number of men such a lord could be expected to field, if necessary.
In the Edo period, samurai stipends were paid in koku, and the gold currency denomination known as the ryô was generally held to be roughly equivalent to one koku in value. Over the course of the period, however, the value of gold rose dramatically relative to the cost of rice, making samurai relying on stipends paid in rice less and less wealthy relative to the merchant class, who earned their incomes in gold and silver.
Daimyô and lower-ranking samurai alike are believed to have themselves enjoyed roughly 35% of the face-value of their stipends (or kokudaka in the case of daimyô), with the rest being paid to retainers or otherwise not coming into the samurai's own personal wallet. For samurai resident in Edo, stipends were paid out of a granary office in Asakusa, in three installments over the course of a year. One-quarter of the annual stipend was paid in spring, one-quarter in summer, and the remaining one-half in the winter. Though stipends were nominally measured in koku of rice, samurai were often paid in a mixture of rice and gold coinage. Those receiving a salary in addition to, or instead of, a rice stipend, were often paid in hyô or "bushels" of rice. One hyô was roughly 2/5 of a koku.
The size of ships was also typically stated by its cargo capacity, measured in koku. By chance, this unit works out to roughly 1/10th of the conventional unit of ship size today, namely tons of displacement. Thus, a 1500-koku ship can be said to have been roughly 150 tons in modern parlance. That was the typical size for, for example, higaki kaisen cargo ships which carried goods between Osaka and Edo.
- Sansom, George. A History of Japan 13334-1615. Stanford: Stanford University Press, 1963.
- Hall, John Whitney. Government and Local Power in Japan 500 to 1700: A Study Based on Bizen Province". Princeton: Princeton University Press, 1966.
- It probably would not feed him very well though. Using modern Japanese figures, one koku of rice a year would mean about 1430 cal/day. The recommended diet for a moderately active male of 150 cm. is about 2000 cal/day and for a quite active male is 3000 cal/day. Though not everything can carry right over, 1 koku of rice a year was probably not really sufficient for the diet of an active warrior or peasant. (Visual Wide Food Composition Tables ヴィジュアルワイド食品成分表, Tokyo Shoseki, 1996)
- Screech, Timon. "Owning Edo-Period Paintings." in Lillehoj, Elizabeth (ed.) Acquisition: Art and Ownership in Edo-Period Japan. Floating World Editions, 2007. p34.
- Craig, Teruko (trans.). Musui's Story: The Autobiography of a Tokugawa Samurai. University of Arizona Press, 1988. p.xv.
- Mining, Monies, and Culture in Early Modern Societies: East Asian and Global Perspectives, Brill (2013), 48.
- Michelle Damian, “Archaeology through Art: Japanese Vernacular Craft in Late Edo-period Woodblock Prints” (MA thesis, East Carolina University, 2010), 105-106.
- Gallery labels, "Higaki-kaisen," Edo-Tokyo Museum.