Hundredweight

Also referred to as centum weight, the hundredweight (cwt) is a unit of mass expressed in terms of pounds. In commodity trading the (short) hundredweight is used as unit for rough rice (RR) future contracts traded at the CBOT.

Imperial system:
1 (long) hundredweight = 112 lb = 50.802345 kg.
20 hundredweight = 1 (long) ton = 2240 lb ≈ 1 metric ton (2205 lb = 1000 kg.)

U.S. customary system:
1 (short) hundredweight = 100 lb = 45.359237 kg.
20 hundredweight = 1 (short) ton = 2000 lb