The koku (石) is a Chinese-based Japanese unit of volume. 1 koku is equivalent to 10 (斗) or approximately 180 litres (40 imp gal; 48 US gal), or about 150 kilograms (330 lb). It converts, in turn, to 100 shō and 1000 gō. One gō is the volume of the "rice cup", the plastic measuring cup that is supplied with commercial Japanese rice cookers. The Chinese equivalent or cognate unit for capacity is the shi or dan (Chinese: 石; pinyin: shí, dàn; Wade–Giles: shih, tan also known as hu (斛; hú; hu), now approximately 103 litres but historically about 59.44 litres (13.07 imp gal; 15.70 US gal).