1 koku is equal to 10 to (a unit of volume, 1 to is about 18 liters), that is, 100 sho (a unit of volume, 1 sho is about 1.8 liters) or 1,000 go (a unit of volume, 1 go is about 0.18 liters).
1石は10斗であり、よって100升、1,000合ということになる。