tonne

Everyday

1. A tonne is a unit of mass equal to one thousand kilograms. tree →
2. Informally, «a tonne» or «tonnes» means a very large amount, as in «tonnes of homework». tree →

In the lessons

In maths and science lessons a tonne is the biggest everyday unit of mass in the metric system: 1 tonne = 1,000 kg. It is used for heavy things like cars, lorries, whales and loads of sand. Problems ask pupils to change tonnes to kilograms (multiply by 1,000) or kilograms to tonnes (divide by 1,000). Phrases: «weighs a tonne», «tonnes of», «a five-tonne truck».

Examples

• An elephant can weigh about six tonnes. tree →
• One tonne is the same as one thousand kilograms. tree →
• The lorry carried twelve tonnes of sand. tree →
• 3 tonnes is 3,000 kilograms. tree →
• This bag weighs a tonne! tree →
• We had tonnes of fun at the fair. tree →
• A blue whale weighs more than one hundred tonnes. tree →
• The bridge sign says the limit is 7.5 tonnes. tree →

Note

Countable noun: one tonne, two tonnes; the symbol is t. «Tonne» (metric tonne) is used in the UK, Australia, New Zealand, Canada and Ireland. Trap: the American «ton» (short ton) is about 907 kg, and the British «ton» (long ton) is about 1,016 kg, so «ton» and «tonne» are not exactly the same. Homophone: «ton» sounds the same. In maths: tonnes × 1,000 = kilograms.