Definition
A metric unit of mass equal to 1,000 kilograms, approximately 2,204.6 pounds. Also called a metric ton.
Plain English
A metric measurement of weight equal to one thousand kilograms, which is a little heavier than the U.S. short ton of 2,000 pounds.
Context Anchor
Seen in international aviation documents, cargo records, aircraft weight information, and performance data that use metric units.
Derivation
From the French tonne, meaning a large cask or barrel. The spelling tonne is used internationally to distinguish the metric unit (1,000 kg) from the U.S. short ton (2,000 lb) and the British long ton (2,240 lb).
Why Pilots Care
Prevents weight miscalculations on international operations where metric units are standard.
Intuition Check
Do not assume tonne and ton always mean the same thing. A tonne is 1,000 kilograms, about 2,204.6 pounds, so it is slightly heavier than a U.S. 2,000-pound ton.
Example Sentence 1
The cargo aircraft was loaded with twelve tonnes of freight before departure.
Example Sentence 2
We loaded 12 tonnes of fuel before the transatlantic crossing.