A metric ton (t), also referred to as a "tonne," is a unit of mass in the metric system of units. It is accepted for use in the International System of Units (SI), but is not an SI unit.
1 metric ton = 1000 kg = 2204.622 lb
1 US ton = 907.18474 kg = 2000 lb
1 imperial ton = 1016.0469 kg = 2240 lb
The various definitions of the ton are all abbreviated as "t." As such, it is important to know which definition of the ton is being used, or to specify which version is being used so as to not confuse their values in the metric, US customary, or imperial systems of measurement.
Metric tons, short tons, and long tons
The metric ton is just one of a number of definitions of the ton. It is the only definition of the ton defined in the International System of Units (SI), and is used to some degree in most of the world.
The term "metric ton" is mostly used in the US to differentiate it from the short ton (US ton), the definition of the ton that is used in the US (and sometimes Canada). Elsewhere, the metric ton is usually referred to as the tonne. The metric ton (1000 kg) has a measure that is slightly larger than the US ton (907.18474 kg). It can also be referred to as 1 megagram (using SI prefixes), but this term is rarely used.
The UK (and other countries that still use the imperial system) uses the long ton (1,016.0469 kg), also referred to as the imperial ton. It is the largest version of the ton and is only used within the UK and certain countries that were former territories of the British Empire that used the imperial system. However, even within the UK and these countries, the long ton is not frequently used. This is because most countries have adopted SI, and since then, have fully shifted, or continue to shift from using imperial units to SI units of measurement.
Did you know??
Metric tons are defined based on the kilogram, while US and imperial tons are defined based on the pound. This is why they have round values when defined using units in their respective systems of measurement.