Convert Kilograms to Stones
Convert kilograms into stones for UK and Irish body-weight conventions. Stones are still commonly used on personal scales in Britain.
1 kg = 0.157473 st
One kilogram equals approximately 0.157473 stone, since one stone is exactly 6.35029318 kg. To convert kilograms to stone, divide by 6.35029318 — so 70 kg = 11.02 st and 80 kg = 12.60 st. The stone remains in everyday use for body weight in the UK and Ireland, though it is no longer used for trade. The formatting is what confuses non-users: British weights are given as stone and pounds, so 70 kg is 11 st 0.4 lb, usually said as "eleven stone". The decimal remainder is pounds out of fourteen, not out of ten, so 11.5 st is 11 st 7 lb rather than 11 st 5 lb. Americans express the same weight in pounds alone — 154 lb — and Australians and Canadians use kilograms, which is why medical forms differ by country. Bathroom scales usually switch between all three.
Quick reference: kilograms to stones
| Kilograms | Stones |
|---|---|
| 6.35 | 1.00 st |
| 50 | 7.87 st (7 st 12.2 lb) |
| 60 | 9.45 st (9 st 6.3 lb) |
| 70 | 11.02 st (11 st 0.3 lb) |
| 75 | 11.81 st (11 st 11.4 lb) |
| 80 | 12.60 st (12 st 8.4 lb) |
| 90 | 14.17 st (14 st 2.4 lb) |
| 100 | 15.75 st (15 st 10.5 lb) |
| 120 | 18.90 st (18 st 12.6 lb) |
How do you convert kilograms to stones?
Formula: stone = kilograms ÷ 6.35029318 • A 70 kg adult → 70 ÷ 6.35029318 = 11.02 st, normally spoken as 11 stone 0 pounds. • An 82 kg weight → 82 ÷ 6.35029318 = 12.91 st, which is 12 stone 12.8 lb — the decimal must be converted to pounds, not read as pounds directly. • A 95 kg weight → 95 ÷ 6.35029318 = 14.96 st, or 14 stone 13.4 lb.
When and why people use kilograms to stones
British and Irish healthcare is where this conversion appears most. Clinical records and prescriptions are metric, but patients overwhelmingly describe their own weight in stones and pounds, so practitioners convert in both directions during almost every consultation involving weight. Fitness and weight tracking is the second context. Apps and scales sold in the UK usually offer a stone display, and someone following a training programme written in kilograms needs to map progress onto the units they actually think in. The third is sport, particularly boxing, horse racing and rowing. Boxing weight divisions are defined in pounds, racing handicaps are quoted in stones and pounds, and lightweight rowing limits are metric — so anyone following these sports across sources encounters all three units for the same underlying quantity.
Common mistakes to watch for when converting kilograms to stones
The dominant error is reading the decimal part of a stone figure as pounds. 12.91 stone is not 12 stone 91 pounds and not 12 stone 9 pounds — the 0.91 must be multiplied by 14 to give 12.8 pounds. Because a stone is 14 pounds rather than 10, decimal intuition fails badly here. A second issue is that the stone is not legal for trade in the UK, so it appears on bathroom scales and in conversation but not on regulated packaging; expecting it in a commercial context leads to confusion. Third, the US does not use the stone at all, so a weight quoted in stones is meaningless to most American audiences and should be converted to pounds before being shared. Finally, avoid the 6.35 rounding for precise work — the exact figure is 6.35029318 kg.
How to estimate kilograms to stones in your head
Divide by 6 and then subtract about 5.5%. For 80 kg: 80 ÷ 6 = 13.33, minus 0.73 gives 12.6 stone, matching the true 12.60. A cleaner route is to convert to pounds first using the double-and-add-a-tenth trick, then divide by 14. For 80 kg: double is 160, plus 16 is 176 lb, and 176 ÷ 14 = 12.57 stone. The two-step method is more reliable because the pound conversion is one most people already know. Anchors: 50 kg ≈ 7 st 12, 60 kg ≈ 9 st 6, 70 kg ≈ 11 st, 80 kg ≈ 12 st 8, 90 kg ≈ 14 st 2, 100 kg ≈ 15 st 10. The critical discipline is remembering that the decimal is out of 14, not 10 — 12.6 stone is 12 st 8 lb, not 12 st 6 lb.
Kilograms to Stones FAQ
How many kg is a stone?
- Exactly 6.35029318 kg, since a stone is 14 pounds and a pound is 0.45359237 kg.
How do I convert the decimal into pounds?
- Multiply it by 14. So 12.91 stone is 12 stone plus 0.91 × 14 = 12.8 pounds.
What is 70 kg in stones and pounds?
- 11 stone 0.3 pounds — normally rounded to 11 stone.
Why is 12.9 stone not 12 stone 9 pounds?
- Because a stone is 14 pounds, not 10. The decimal is a fraction of 14, so 0.9 stone is 12.6 pounds.
Is the stone still legal for trade?
- No. It was removed from legal trade use in the UK but remains common for body weight in speech and on bathroom scales.
Do Americans use stones?
- No. Convert to pounds before sharing a weight with a US audience — 11 stone is 154 lb.
How many pounds in a stone?
- 14 pounds exactly.
Is my weight sent to a server?
- No. The calculation runs entirely in your browser.
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Sources: UK Weights and Measures Act 1985 and subsequent metrication regulations; 1959 international yard and pound agreement (1 stone = 14 lb = 6.35029318 kg); NHS clinical weight recording guidance.