• 3-minute read
• 29th November 2019

Word Choice: Ton vs. Tonne

We have a ton of proofreading to do right now! Or should that be a ‘tonne’? We won’t blame you if you’re not sure, as there aren’t many words in English that are easier to mix up than ton and tonne.

As well as being similar in spelling, these terms both refer to a measure of mass. However, despite this, these words are not interchangeable (nor are the masses they denote). Sound confusing? You bet it is! Check out our guide below to make sure you know how to use ‘ton’ and ‘tonne’ correctly.

Ton (Imperial Measurement = 1,016.047 kg)

A ‘ton’ is an imperial unit of measurement, like an inch or a pint. However, a ton is a unit of mass equivalent to 1,016.047 kg (or 2,240 lbs to use another imperial measure). In the UK, we usually just call this a ‘ton’. But in the USA, it is more often called a ‘long ton’ or an ‘imperial ton’. This is because North America has its own ‘ton’ (more on that below).

More colloquially, a ‘ton’ can be any large amount of something. For instance:

If you spell this word wrong, I’ll come down on you like a ton of bricks!

This doesn’t mean exactly 1,016.047 kg of bricks. Rather, when we say a ‘ton’ of something, we simply mean to evoke a heavy weight. As such, it is like the ‘ton’ of proofreading we mentioned in the first line of this post!

Tonne (Metric Measurement = 1,000 kg)

A ‘tonne’ is a metric unit of measurement. As with the imperial ton, it measures mass, but a metric tonne weighs 1,000 kg (or 2,204.6 lbs in imperial terms). It is therefore slightly lighter.

Unlike ‘ton’, moreover, we would not usually use this word colloquially to mean ‘a lot of’ something. For example, we wouldn’t refer to a ‘tonne of bricks’ even though ‘like a ton of bricks’ is a common saying.

The North American Ton

Did you think having two similar measures of mass with identical pronunciations but different spellings was confusing enough? Well, let us introduce the North American ‘short’ ton.

Spelled the same as the British ‘long ton’, the short ton is a unit of mass equivalent to 907.18474 kg (or 2,000 lbs). Why are they all called tons? We couldn’t find a good explanation, so we assume it’s purely to make spelling these words correctly a living nightmare.

Regardless, if you’re writing for a US audience, remember:

• A ‘ton’ is a North American short ton (907.18474 kg or 2,000 lbs).
• An ‘imperial ton’ is a British long ton (1,016.047 kg or 2,240 lbs).
• A ‘metric ton’ is a tonne (1,000 kg or 2,204.6 lbs).

The most common unit in the US and Canada is the ‘short ton’, though.

Summary: Ton vs. Tonne

Although they sound the same and both refer to a unit of mass, there is a difference between the words ‘ton’ and ‘tonne’ beyond just spelling:

• A ton is an imperial unit of mass equivalent to 1,016.047 kg or 2,240 lbs.
• A tonne is a metric unit of mass equivalent to 1,000 kg or 2,204.6 lbs.

In addition, keep in mind that the North American ‘ton’ different from both of the above. Thus, if you’re writing for a US-based audience, you may need to say ‘long ton’ or ‘imperial ton’ to distinguish it from the lighter American ‘short ton’, which is typically just known as a ‘ton’.

Hopefully, this has helped you understand the difference between these terms! However, since typos are still easy to miss, don’t forget to have your written documents checked by the experts.