Updated September 2026
Stone to Kilogram
Instantly convert stone to kilogram with fast, accurate, real-time results.
Contents
The stone is a unit of body weight still widely used in the United Kingdom and Ireland. If your scales display stone and pounds (e.g., "11 st 4 lbs"), this page helps you convert to kilograms — the standard metric unit used in medical records and sports science worldwide.
One stone equals exactly 14 pounds. To convert to kilograms, multiply by 6.35029 (the exact metric equivalent of 14 lbs). For mixed readings (stone + lbs), convert both parts separately and add them together.
The Conversion Formula
For stone + lbs combined:
kg = (stone × 14 + lbs) × 0.453592
The factor 6.35029 comes from the exact definition: 1 stone = 14 lbs, and 1 lb = 0.45359237 kg exactly, so 14 × 0.45359237 = 6.35029318 kg.
What Is a Stone?
The stone is a traditional British unit of weight defined as 14 avoirdupois pounds. It has been used in the UK for centuries and was historically applied to commodities like grain, cheese, and livestock — with the value varying by commodity. In 1835, the UK standardised the stone at 14 pounds for all purposes.
Today the stone is primarily used for personal body weight in the UK and Ireland. It does not appear in US measurements (Americans use pounds only), and it is not part of the metric system. However, most UK gym equipment, NHS records, and medical literature now use kilograms as the primary unit.
Visual Guide
Common Stone Values in Kilograms
| Stone | Kilograms | Pounds | Notes |
|---|---|---|---|
| 1 st | 6.35 kg | 14 lbs | Definition: 1 stone = 14 lbs exactly |
| 5 st | 31.75 kg | 70 lbs | Typical weight for a 10-year-old child |
| 7 st | 44.45 kg | 98 lbs | Below average adult weight |
| 8 st | 50.80 kg | 112 lbs | Light adult weight |
| 9 st | 57.15 kg | 126 lbs | Average female (UK, lower range) |
| 10 st | 63.50 kg | 140 lbs | Average female (UK) |
| 11 st | 69.85 kg | 154 lbs | Average weight, mixed adults |
| 12 st | 76.20 kg | 168 lbs | Average male (UK, lower range) |
| 13 st | 82.55 kg | 182 lbs | Average male (UK) |
| 14 st | 88.90 kg | 196 lbs | Heavier adult |
| 15 st | 95.25 kg | 210 lbs | Overweight for most heights |
| 16 st | 101.60 kg | 224 lbs | Clinically obese for average height |
| 18 st | 114.30 kg | 252 lbs | — |
| 20 st | 127.01 kg | 280 lbs | — |
Converting Stone + Pounds to kg
UK bathroom scales often display body weight in combined stone and pounds format, such as "12 st 7 lbs". To convert this to kilograms:
- Convert the stone part: 12 × 6.35029 = 76.20 kg
- Convert the remaining pounds: 7 × 0.453592 = 3.18 kg
- Add them: 76.20 + 3.18 = 79.38 kg
= (12 × 14 + 7) × 0.453592
= 175 lbs × 0.453592
= 79.38 kg
Full Reference Table (1–25 stone)
| Stone | kg | lbs | Stone | kg | lbs |
|---|---|---|---|---|---|
| 1 st | 6.35 kg | 14 | 14 st | 88.90 kg | 196 |
| 2 st | 12.70 kg | 28 | 15 st | 95.25 kg | 210 |
| 3 st | 19.05 kg | 42 | 16 st | 101.60 kg | 224 |
| 4 st | 25.40 kg | 56 | 17 st | 107.95 kg | 238 |
| 5 st | 31.75 kg | 70 | 18 st | 114.31 kg | 252 |
| 6 st | 38.10 kg | 84 | 19 st | 120.66 kg | 266 |
| 7 st | 44.45 kg | 98 | 20 st | 127.01 kg | 280 |
| 8 st | 50.80 kg | 112 | 21 st | 133.36 kg | 294 |
| 9 st | 57.15 kg | 126 | 22 st | 139.71 kg | 308 |
| 10 st | 63.50 kg | 140 | 23 st | 146.06 kg | 322 |
| 11 st | 69.85 kg | 154 | 24 st | 152.41 kg | 336 |
| 12 st | 76.20 kg | 168 | 25 st | 158.76 kg | 350 |
| 13 st | 82.55 kg | 182 | — | — | — |
Frequently Asked Questions
How many kg is 1 stone?
1 stone = 6.35029 kilograms (exactly). Since 1 stone = 14 pounds and 1 pound = 0.45359237 kg exactly, the conversion is 14 × 0.45359237 = 6.35029318 kg.
How do I convert 12 stone to kg?
Multiply by 6.35029: 12 × 6.35029 = 76.20 kg. Alternatively: 12 stone = 168 lbs, and 168 × 0.453592 = 76.20 kg. Both methods give the same answer.
What countries use stone as a unit of weight?
The stone is primarily used in the United Kingdom and Ireland for body weight. It is not used in the United States (where pounds are used instead), and it is not part of the metric system used in most of the rest of the world. British and Irish TV shows, sports commentary, and health discussions often express weight in stone.
What is 11 stone 7 lbs in kg?
11 st 7 lbs = (11 × 14 + 7) × 0.453592 = 161 × 0.453592 = 73.03 kg. First multiply the stone by 14 to get total pounds, add the remaining pounds, then multiply the total by 0.453592.
Is 14 stone overweight?
It depends on your height. 14 stone = 88.9 kg. For someone 175 cm (5 ft 9 in) tall, BMI = 88.9 ÷ (1.75²) = 29.0, which is at the top of the overweight range (BMI 25–29.9). For a taller person (e.g., 185 cm), the same weight gives BMI = 26.0, which is lightly overweight. BMI is one indicator — your doctor can give a more complete assessment.
How many stone is 70 kg?
70 kg ÷ 6.35029 = 11.02 stone, or approximately 11 stone 0.3 lbs. To be more precise: 11 × 6.35029 = 69.85 kg, so the remainder is 70 − 69.85 = 0.15 kg = 0.33 lbs, giving 11 st 0 lbs (rounded). Use the kg to stone converter for the reverse calculation.
Sources
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