Weight & Mass Converter
Convert mass units across international metric standards and avoirdupois imperial systems. Calculated using the 1959 International Agreement definition: 1 avoirdupois pound is exactly 0.45359237 kilograms.
In physics, mass is the intrinsic quantity of matter inside an object (measured in kilograms), which remains identical whether on Earth, the Moon, or deep space. Weight is the gravitational force exerted upon that mass ($W = m \\cdot g$), measured in Newtons or pound-force. In everyday commerce, the word "weight" universally refers to mass.
There are three distinct "tons" in active global circulation: the US Short Ton (2,000 lbs / 907.18 kg), the British Long Ton (2,240 lbs / 1,016.05 kg), and the Metric Tonne (1,000 kg / 2,204.62 lbs). Always verify contract specifications when booking international freight!