⚖️ Weight Conversions
How Many Stone in a Tonne?
One metric tonne is 1,000 kg, and one stone is 6.35029318 kg. Divide the two and you get about 157.47 stone per tonne. Here is what that means in the real world.
The Maths: Why 157.47?
The conversion is exact, not approximate, because both units are legally defined. A tonne is defined as exactly 1,000 kilograms. A stone is defined as exactly 14 pounds, and the international pound is defined as exactly 0.45359237 kg, making the stone exactly 6.35029318 kg. So:
1,000 ÷ 6.35029318 = 157.4730444 stone
In practice, "about 157 and a half stone" is all you need. Going the other way, one stone is 0.00635 tonnes, so multiply stone by 157.47 to get tonnes, or divide stone by 157.47. This is not a converter page: it is the explanation of a conversion almost nobody needs daily but everyone gets curious about.
Tonne vs Ton: Three Different "Tons"
The reason this question confuses people is that English has three different tons. They are close in size but not identical, and each converts to a different number of stone:
| Unit | Definition | In stone |
|---|---|---|
| Tonne (metric ton) | 1,000 kg | 157.47 |
| Long ton (imperial ton) | 2,240 lb | 160 exactly |
| Short ton (US ton) | 2,000 lb | 142.86 |
Notice something elegant: the imperial long ton is exactly 160 stone, because it is defined as 20 hundredweight, each hundredweight is 8 stone, and 20 × 8 = 160. The imperial system was designed so its big units resolve to whole numbers of stone. The metric tonne lands on the awkward 157.47 only because it was defined without any reference to the stone at all. Our stone vs hundredweight guide shows how the whole imperial ladder fits together.
When Would You Ever Convert Stone to Tonnes?
Almost never in personal life. Nobody weighs 157 stone. But the conversion surfaces wherever imperial habits collide with metric industry:
- Shipping and freight: a UK customer thinks in stone for body weight but books freight in tonnes. Moving companies and parcel carriers (see our parcel weight guide) quote in kg, and customers sometimes want the stone equivalent for intuition.
- Vehicle weights: a car's kerb weight might be listed as 1.4 tonnes in the brochure. That is about 220 stone, which means nothing to anyone, but the reverse question ("how many stone is my car's weight?") gets asked out of curiosity.
- Construction and aggregates: builders order hardcore, sand, and gravel by the tonne. Older tradespeople who grew up with hundredweight and stone sometimes do the mental conversion.
- Livestock: cattle are weighed in kilograms commercially, but auction-ring banter still uses imperial. A prize bull at 1,000 kg is, technically, 157 stone.
For everyday body-weight conversions, you want our stone to kg chart instead. This page is for the curious and for the handful of professional contexts where the two systems meet.
Frequently Asked Questions
How many stone are in a tonne?
One metric tonne (1,000 kg) equals about 157.47 stone. In round numbers, a tonne is roughly 157 and a half stone.
How many stone are in a ton (imperial)?
The imperial long ton is 2,240 pounds, which is exactly 160 stone. The American short ton is 2,000 pounds, which is about 142.86 stone. Always check which ton is meant.
How do you convert stone to tonnes?
Divide the number of stone by 157.47. For example, 315 stone divided by 157.47 is almost exactly 2 tonnes.
When would you convert between stone and tonnes?
Rarely in daily life. The conversion comes up in shipping, construction, vehicle weights, and when reading technical specifications that mix imperial body-weight units with metric freight units.