Currency Museum Bank of Japan
FAQ currency

Q3. What were the currency units used during the Edo Period (1603-1868)?

A3. During the Edo Period, the Tokugawa Shogunate government employed a tri-metallic monetary system based on gold, silver, and copper coins. Gold coins had face values based on the quaternary system, with the denomination of one Koban gold coin being set at 1 ryo, equivalent to 4 bu and to 16 shu, while silver coins were traded by weight with monme used as the basic unit of 1 monme, equivalent to 3.75 grams. Finally, one copper coin had the denomination of 1 mon (1,000 mon = 1 kanmon).

The official exchange rate was set by the Tokugawa Shogunate government -- in the 18th century, 1 ryo of gold equaled 60 monme of silver or 4,000 mon of copper -- but in practice these three types of coins were exchanged at market rates.