A stone is a traditional unit of weight used in the United Kingdom and Ireland for measuring body weight. It is equal to 14 pounds or approximately 6.35 kilograms. The stone continues to be used in customary practice in the United Kingdom for body weight
. The stone was originally any good-sized rock chosen as a local standard, but it came to be widely used as a unit of weight in trade, with its value fluctuating with the commodity and region. In the 14th century, England's exportation of raw wool to Florence necessitated a fixed standard, and a royal statute fixed the stone of wool at 14 pounds
