Tonne
The tonne is a metric unit of mass equal to 1,000 kilograms. It is also called the metric ton.
Kilogram: The SI base unit of mass, defined by fixing the numerical value of the Planck constant. One thousand kilograms make one tonne.
Short ton: A United States customary unit of mass equal to 2,000 pounds. It is lighter than a tonne and is commonly called a ton in the United States.
Metric tonne: A unit of mass equal to 1,000 kilograms, often used to distinguish it from other tons. This name explicitly identifies the tonne in international trade and technical reporting.
Metrication: The adoption of the metric system by a country or institution. Metrication established the tonne as a practical mass unit in places that adopted decimal measures.
Metric system: A decimal system of measurement whose units are related by powers of ten. The tonne belongs to its decimal family of mass units.
Long ton: A British imperial unit of mass equal to 2,240 pounds. It is heavier than a tonne and historically served in British trade and shipping.
Deadweight tonnage: A measure of a ship's total carrying capacity, including cargo, fuel, crew, and supplies. Shipping uses tonnes to quantify the mass a vessel can carry.
French Revolution: A period of political and social upheaval in France from 1789 to 1799. The metric system that includes the tonne arose from revolutionary-era French reforms.
Metric prefix: A prefix attached to a unit name or symbol to indicate a decimal multiple or fraction. The prefix kilo- means one thousand, the factor linking tonnes to kilograms.
Pound (mass): A unit of mass equal to 0.45359237 kilograms. Pounds provide the conversion basis for comparing tonnes with customary tons.