🌾 Koku Volume Converter (石 to L)

The Koku Volume Converter converts the koku (石), the largest commonly referenced traditional Japanese volume unit. One koku equals 10 to (斗), 100 sho (升), or 1000 go (合) - approximately 180.39 liters.

Historically, the koku was far more than a volume measure - it was the economic unit of feudal Japan. Samurai stipends were paid in koku of rice. Domain wealth was measured in "koku-daka" (石高). A daimyo needed at least 10,000 koku to qualify as a feudal lord.

The koku was abolished as a legal unit in the Meiji era but remains culturally significant. It appears in historical dramas (jidaigeki), period literature, and discussions of Edo-period economics.

Conversion formula:

The shakkanho volume system is fully decimal:

• 1 koku = 10 to (斗)
• 1 to = 10 sho (升)
• 1 sho = 10 go (合)

In weight terms, 1 koku of polished white rice weighs approximately 150 kg (330 lbs). The conversion 1 koku = 180.39 L is based on the 1891 Japanese Weights and Measures Act.

For everyday cooking, use our go converter or sho converter. For general liquid measurements, the volume converter covers metric and imperial. The shakkanho bundle converter includes all traditional units.

1. Enter the value in koku (e.g. 100 for a minor samurai stipend).
2. Select the target unit (liters, sho, gallons, etc.).
3. Click Convert to see the result.
4. Compare with the historical reference table.

How many liters is one koku?

One koku equals 180.39 L (exactly 1000 x 2401/13310 liters). It is the largest standard unit in the shakkanho volume system, equal to 100 sho or 1000 go.

What was a koku of rice worth?

During the Edo period, 1 koku of rice (approx. 150 kg) represented roughly one person annual food supply. Its monetary value varied by era and region, but averaged 1-2 ryo (gold coins) during the late Edo period.

How much does 1 koku of rice weigh?

One koku of polished white rice weighs approximately 150 kg (330 lbs). The exact weight varies by rice variety, polishing degree, and packing density. Brown rice is slightly heavier per koku.

What was the minimum koku for a daimyo?

A feudal lord (daimyo) needed a domain producing at least 10,000 koku of rice annually. This threshold, established by the Tokugawa Shogunate, ensured the lord could maintain a residence, retainers, and military obligations.

Is koku still used today?

The koku is no longer an official measurement unit in Japan. However, sake breweries still use it informally to describe production volume (e.g. "a 5,000-koku brewery"). Historical dramas, museums, and academic discussions also keep the unit alive.

One koku = one year of rice for one person. This was the Edo-period standard for calculating samurai stipends. A 100-koku samurai had enough to feed approximately 100 people, covering family and retainers.

Domain wealth (koku-daka) determined political power. The Tokugawa Shogunate held about 4 million koku directly. Major domains: Kaga (1.02M), Satsuma (770K), Sendai (620K). A 10,000-koku domain was the minimum to be recognized as a daimyo.

Weight of 1 koku of rice is approximately 150 kg, not a fixed number, because the koku measures volume. Different rice varieties and polishing levels change the density. The 150 kg figure is for standard polished white rice.

In modern context, 1 koku (180 L) is about the volume of a standard oil drum (200 L). It is occasionally used in sake production - large breweries measure annual output in koku.