The term British Weight refers to a system of measurements used in the United Kingdom. The system includes the gramme, which is a unit of mass equal to one thousandth of a kilogram; the STONE, which is a unit of mass equal to fourteen pounds; the TON, which is a unit of mass equal to two thousand pounds; the tonne, which is a metric unit of mass equal to one thousand kilograms; the CARAT, which is a unit of mass equal to four hundred milligrams; and the TARE, which is a unit of mass equal to the weight of a container and its contents.