At first there were different units depending on the time and region, but these were unified in 1669.
1 Koku equals:
In 1891 1 Shō was defined as 2401 ⁄ 1331 liters ≈ 1.8039 l and thus a koku about 180.39 l.
A koku is defined as 10 cubic shaku (1 shaku = 10 ⁄ 33 m) as wood volume and as loading capacity in shipbuilding , which in metric dimensions corresponds to 10 · ( 10 ⁄ 33 m) 3 ≈ 0.278 m³ ≈ 278 l.
The rice production is in Koku measured using a Koku was defined as the amount of dry rice grains consumed an adult in one year. The equivalent in money corresponded to about 1 ryō (since 1871 yen ) in average harvest years and could rise in line with demand in the event of poor harvests and inflation. For example, in 1891 the price per koku (1.8 hectoliters) was 6.32 to 7.35 yen and rose to 10.28 to 11.93 yen by 1900.
The current equivalent of a ryō can only be determined approximately: Based on the mean value of the fluctuations in the gold price over the past three decades, 1 ryō would be around 350,000 yen or 2000 euros (fluctuation range 1750–2300 euros). The ratio would look much less favorable when measured against the development of purchasing power. Accordingly, 1 ryō would only be worth around 100 euros today.
It used to be the case that a person's assets or wages were given in koku rice per year - kokudaka ( 石 高 ). A daimyo had at least 10,000 koku rice per year. However, the bulk of the samurai were usually only poorly paid, sometimes even below the subsistence level of a family.
Below are the families with a nominal travel income ( 表 高 , omotedaka ) of over half a million koku , i.e. H. the numbers are based on the information given in the shogunate . There can therefore be considerable discrepancies with real income ( 内 高 , uchidaka ).
|1.||( Tenryō )||Tokugawa shogunate family||4,000,000|
- exception of the Hatamoto lands , which totaled 2.5 million koku, and daimyo lands retained by the shogunate, with a total of 500,000 koku.
Japan's total travel income was 30 million koku.
- Eduard Döring: Handbook of coin, exchange, measure and weight. Verlag J. Hölscher, Koblenz 1862, p. 236