- Posted by Stephen Whiteley
- On 12/06/2015
What is the difference between the UK and US ton?
A common source of confusion to translators and engineers alike is the difference between the UK and the US ton. In the US and Canada, a ton is equal to 20 hundredweight, which means it weighs 2000 pounds, or 907.185 kilograms.
In the UK, confusingly, there are 112 pounds to the hundredweight, and therefore 2240 pounds (1016.047 kg) to the ton.
A ton (or tun) originally meant a cask of wine, which was the traditional unit of measurement for the carrying capacity of a ship (this probably explains the fact that the UK ton is so imprecise a quantity: it was only intended to give a general idea of the volume of a ship’s hold.)
To distinguish between these two measures, a UK ton is called a long ton, while a US ton is a short ton.
Naturally, the metric tonne (Spanish: una tonelada, French une tonne) is another weight altogether, namely 1000 kg, or megagram. The metric tonne may also be spelt ton but (in standard English, at least) the pronunciation does not change