A dan or shi () in China, koku in Japan and seok () in Korea, is a unit of volume mainly for grains. It originated in China and later spread to other places in East Asia. One dan is divided into 10 dous or 100 shengs. It is 100 litres in China, 180.39 litres in Japan and 180 litres in Korea.
For more details, please see Sheng (volume)