Stone (unit)

The stone or stone weight (abbreviation: st.) is an English and imperial unit of mass equal to 14 pounds (approximately 6.35 kg). The stone continues in customary use in the United Kingdom and Ireland for body weight.

England and other Germanic-speaking countries of northern Europe formerly used various standardised "stones" for trade, with their values ranging from about 5 to 40 local pounds (roughly 3 to 15 kg) depending on the location and objects weighed. With the advent of metrication, Europe's various "stones" were superseded by or adapted to the kilogram from the mid-19th century on.