A stone is a unit of weight equal to 14 pounds averdupois (or international lbs). By turn, this makes a stone equivalent to 6.35029kg.
Before approximately the 14th century there were two hundredweights in England, one of 100 pounds, and one of 108 pounds. In 1340, King Edward III changed the value of the stone from 12 pounds to 14 pounds. Since a hundredweight is 8 stones, the 100-pound hundredweight became 112 pounds.