What does tonne mean?
A tonne is a metric unit of mass equal to 1,000 kilograms, roughly the weight of a small adult elephant. It is especially common in British English and in contexts involving shipping, transport, recycling, emissions, and bulk materials, where measurements such as “per tonne” or “tonne-kilometre” are useful. The word also has an informal British use meaning a very large quantity: “a tonne of work” or “a tonne of rubbish.” Although it resembles “ton,” tonne has a precisely defined metric meaning, while ton can refer to several nonmetric units. The spelling with an extra “n” helps distinguish the metric measure from those traditional ton units.
nounA tonne is a metric unit of mass equal to 1,000 kilograms. In informal British English, it can also mean a very large quantity of something.
- A unit of mass equal to 1,000 kilograms.
- An informal, chiefly British expression for a very large quantity or amount of something.
"The recycling facility processed more than a tonne of waste last week."
"Each electric truck can carry up to 3.5 tonnes of cargo."
"There is a tonne of work waiting for us to get through."
The plural is formed by adding -s. Use the singular form after a unit expression such as “per tonne.”
"The warehouse stores several tonnes of grain."
The extra “n” in tonne is a useful signal: it names the metric ton, exactly 1,000 kilograms—not a short or long ton.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does tonne come from?
English borrowed tonne from Old French tonne, which developed from medieval Latin tonna, a word associated with a barrel or a unit of weight. The deeper origin of the Latin term is uncertain, so it is best treated as a conventional English etymology rather than traced to a definite source. The related English words ton, tun, tonnage, and tunnage preserve the same older French and Latin vocabulary.
Related word forms
How tonne is actually used
The unit use is formal and technical, though “tonne” is also widely used in everyday British English. The quantity sense is informal and normally appears in phrases such as “a tonne of work” or “a tonne of rubbish.” In the United States, “metric ton” is generally preferred.
Easily confused with tonne
A tonne is the metric unit equal to 1,000 kilograms, whereas a ton is a nonmetric unit and may mean a short ton of about 907 kilograms or a long ton of about 1,016 kilograms.