Avoirdupois

The avoirdupois ( /ˌævərdəˈpɔɪz/; ) system (abbreviation: avdp) is a system of weights (or, properly, mass) based on a pound of 16 ounces. It is the everyday system of weight used in the United States and is still used to varying degrees in everyday life in the United Kingdom, Canada and some other former British colonies despite the official adoption of the metric system. An alternative system of mass is generally used for precious materials, Troy weight. The modern definition of the avoirdupois pound is exactly 0.45359237 kilograms.