One stone is exactly 14 pounds, or 6.35 kg. To convert stone to pounds, multiply by 14 and add any extra pounds: 11 st 4 lb is 158 lb (71.7 kg). To go back, divide pounds by 14 — the whole number is stones, the remainder pounds.
Convert weight between stones and pounds, pounds and kilograms in any direction. Enter weight the British way (e.g. 11 st 4 lb) or as a single number in lb or kg.
How to use this calculator
- Choose what you have: stones and pounds, pounds only, or kilograms.
- For stones and pounds, enter each part separately (for 11 st 4 lb, type 11 and 4).
- Read the headline result, then the same weight in kilograms, pounds and decimal stone underneath.
- Copy the share link to keep the conversion, for example to send a weight to a doctor's office that uses a different unit.
How it's calculated
The stone and pound are defined in Schedule 1 of the UK Weights and Measures Act 1985 and in NIST Handbook 44: 1 stone = 14 lb, and 1 lb = 0.45359237 kg exactly. So:
pounds = stones × 14 + extra poundskg = pounds × 0.45359237stones = floor(pounds ÷ 14),remaining lb = pounds − stones × 14decimal stone = pounds ÷ 14(11.5 st means 11 st 7 lb, not 11 st 5 lb)
The calculator rounds pounds to one decimal before splitting into stones, so a value like 209.96 lb shows as 15 st 0 lb rather than 14 st 14 lb.
Worked examples
1. 11 st 4 lb to pounds and kg
11 × 14 = 154, plus 4 = 158 lb. 158 × 0.45359237 = 71.67 kg.
2. 85 kg to stones and pounds
85 ÷ 0.45359237 = 187.39 lb. 187.39 ÷ 14 = 13.385, so 13 whole stones (182 lb) with 5.4 lb left: 13 st 5.4 lb.
3. 200 lb to stone
200 ÷ 14 = 14.286. 14 stones is 196 lb, leaving 4 lb: 14 st 4 lb, or 90.7 kg.
Stone to pounds and kg chart
| Stone | Pounds | Kilograms | Stone | Pounds | Kilograms |
|---|---|---|---|---|---|
| 6 st | 84 | 38.1 | 17 st | 238 | 108.0 |
| 7 st | 98 | 44.5 | 18 st | 252 | 114.3 |
| 8 st | 112 | 50.8 | 19 st | 266 | 120.7 |
| 9 st | 126 | 57.2 | 20 st | 280 | 127.0 |
| 10 st | 140 | 63.5 | 21 st | 294 | 133.4 |
| 11 st | 154 | 69.9 | 22 st | 308 | 139.7 |
| 12 st | 168 | 76.2 | 23 st | 322 | 146.1 |
| 13 st | 182 | 82.6 | 24 st | 336 | 152.4 |
| 14 st | 196 | 88.9 | 25 st | 350 | 158.8 |
| 15 st | 210 | 95.3 | 26 st | 364 | 165.1 |
| 16 st | 224 | 101.6 | 27 st | 378 | 171.5 |
Half-stone steps in kg
Every half stone is 7 lb. Use this table when one record is in stones and another in kilograms.
| Stone and pounds | Pounds | Kilograms |
|---|---|---|
| 9 st 0 lb | 126 | 57.2 |
| 9 st 7 lb | 133 | 60.3 |
| 10 st 0 lb | 140 | 63.5 |
| 10 st 7 lb | 147 | 66.7 |
| 11 st 0 lb | 154 | 69.9 |
| 11 st 7 lb | 161 | 73.0 |
| 12 st 0 lb | 168 | 76.2 |
| 12 st 7 lb | 175 | 79.4 |
| 13 st 0 lb | 182 | 82.6 |
| 13 st 7 lb | 189 | 85.7 |
| 14 st 0 lb | 196 | 88.9 |
| 14 st 7 lb | 203 | 92.1 |
| 15 st 0 lb | 210 | 95.3 |
Kilograms to stone and pounds chart
| kg | Stone and pounds | kg | Stone and pounds |
|---|---|---|---|
| 45 | 7 st 1.2 lb | 90 | 14 st 2.4 lb |
| 50 | 7 st 12.2 lb | 95 | 14 st 13.4 lb |
| 55 | 8 st 9.3 lb | 100 | 15 st 10.5 lb |
| 60 | 9 st 6.3 lb | 105 | 16 st 7.5 lb |
| 65 | 10 st 3.3 lb | 110 | 17 st 4.5 lb |
| 70 | 11 st 0.3 lb | 115 | 18 st 1.5 lb |
| 75 | 11 st 11.3 lb | 120 | 18 st 12.6 lb |
| 80 | 12 st 8.4 lb | 125 | 19 st 9.6 lb |
Pounds to stone chart
| lb | Stone and pounds | lb | Stone and pounds |
|---|---|---|---|
| 100 | 7 st 2 lb | 180 | 12 st 12 lb |
| 110 | 7 st 12 lb | 190 | 13 st 8 lb |
| 120 | 8 st 8 lb | 200 | 14 st 4 lb |
| 130 | 9 st 4 lb | 210 | 15 st 0 lb |
| 140 | 10 st 0 lb | 220 | 15 st 10 lb |
| 150 | 10 st 10 lb | 230 | 16 st 6 lb |
| 160 | 11 st 6 lb | 240 | 17 st 2 lb |
| 170 | 12 st 2 lb | 250 | 17 st 12 lb |
Converting weight loss or gain
Weight changes convert the same way as weights. Losing 1 stone is losing 14 lb, or 6.35 kg. Losing 5 kg is 11.02 lb, a little under a stone. Losing half a stone is 7 lb (3.18 kg). If you log progress in one unit and your clinic or app uses another, convert the start and end weights and subtract, rather than converting a rounded difference.
| Change | Pounds | Kilograms |
|---|---|---|
| 0.5 st | 7 | 3.18 |
| 1 st | 14 | 6.35 |
| 1.5 st | 21 | 9.53 |
| 2 st | 28 | 12.7 |
| 3 st | 42 | 19.05 |
| 5 st | 70 | 31.75 |
The rest of the British weight table
The stone belongs to the British avoirdupois table that NIST reproduces in Handbook 44, Appendix C. Above the stone come larger units you may meet in older records:
- Quarter: 2 stones = 28 lb (12.7 kg).
- Hundredweight (cwt): 4 quarters = 112 lb (50.8 kg), or 8 stone.
- Ton: 20 hundredweight = 2,240 lb (1,016 kg), or 160 stone. This long ton is heavier than the 2,000 lb US ton.
Using stone for body weight and BMI
BMI is always worked out in metric: weight in kilograms divided by height in metres squared, as the CDC defines it. If you weigh yourself in stones, convert to kg first. For example, 12 stone is 76.2 kg; at 1.75 m tall that is a BMI of 24.9.
The CDC classes an adult BMI of 18.5 to less than 25 as a healthy weight, 25 to less than 30 as overweight and 30 or more as obesity. The NHS uses the same 25 and 30 cut-offs for most adults, but lower ones — 23 for overweight and 27.5 for obese — for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds.
BMI is a screening number, not a diagnosis. For advice about your own weight, speak to your GP or doctor. If you're tracking a goal, the weight loss date calculator estimates when you'll reach it, and the body recomposition calculator helps if you're losing fat and gaining muscle at the same time.
Giving your weight in another country
If you are used to stones and need to fill in a US form, give pounds: multiply stones by 14 and add the extra pounds. For a form, clinic or airline that works in metric, give kilograms, which is pounds × 0.45359237. Going the other way, a US weight in pounds divides by 14 to give stones, and a European weight in kilograms divides by 6.35 to give decimal stone, which the calculator splits into stones and pounds for you. One decimal place in kilograms or pounds is enough for body weight.
- Reading decimal stone as stones and pounds. 12.5 stone is 12 st 7 lb, not 12 st 5 lb, because a stone has 14 pounds, not 10.
- Rounding the kg factor too far. The exact factor is 6.35029 kg per stone. Rounding to 6.3 or 6.4 is off by 0.6 kg at 12 stone, and the error grows with weight.
- Forgetting the extra pounds. 11 st 4 lb is not 11 × 14; add the 4 lb.
- Confusing the hundredweight. In the British table a hundredweight is 112 lb (8 stone). The US hundredweight is 100 lb.
Frequently asked questions
How many pounds in a stone?
Exactly 14 pounds. 1 stone = 6.35 kg.
How do you convert stone to pounds?
Multiply stones by 14 and add the extra pounds: 11 st 4 lb = 11 × 14 + 4 = 158 lb.
How do you convert pounds to stone?
Divide by 14. The whole number is stones and the remainder is pounds: 200 lb ÷ 14 = 14 st 4 lb.
How many kg is a stone?
1 stone = 14 × 0.45359237 = 6.3503 kg, so 10 stone is 63.5 kg.
How do you convert kg to stone and pounds?
Divide kg by 0.45359237 to get pounds, then divide by 14. 70 kg = 154.3 lb = 11 st 0.3 lb.
What is 10 stone in pounds?
10 stone = 140 lb (63.5 kg).
What is 12 stone in kg?
12 stone = 168 lb = 76.2 kg.
What is 100 kg in stone?
100 kg = 220.5 lb = 15 st 10.5 lb.
How many pounds is 15 stone?
15 stone = 210 lb, or 95.3 kg.
How many pounds is half a stone?
Half a stone is 7 lb, or 3.18 kg. 9.5 stone is therefore 9 st 7 lb = 133 lb.
Who uses stones?
Stones are used for body weight in the UK and Ireland. Most other countries use kilograms, and the US uses pounds.
Why is a stone 14 pounds?
It is defined that way in UK law (Weights and Measures Act 1985, Schedule 1) and in the British avoirdupois table NIST reproduces in Handbook 44. The same table has 2 stones to a quarter (28 lb) and 4 quarters to a hundredweight (112 lb).
Sources & method
- UK Weights and Measures Act 1985 — 1 stone = 14 lb; 1 lb = 0.45359237 kg
- NIST Handbook 44 (2026), Appendix C — 14 pounds = 1 stone; 2 stones = 1 quarter; 1 lb = 0.453 592 37 kg
- CDC — Adult BMI categories and formula
- NHS — Obesity: BMI thresholds, including lower thresholds for some ethnic groups
Results are estimates for general information. Found an error? It helps everyone — see our methodology.