Lbs to Stone Converter
Use this lbs to stone converter to change pounds into stone and pounds, decimal stone and kilograms in one step.
Updated October 15, 2026
Medical Disclaimer: This calculator provides a general estimate based on established research and is for educational purposes only, not a substitute for medical advice. Individual results can vary based on health conditions, so consult a qualified healthcare professional or registered dietitian before making significant changes to your diet, exercise, or health routine. Read our full Medical Disclaimer.
How Pounds to Stone Conversion Is Calculated
A stone (st) is a British unit of weight. One stone is 14 pounds. If you live in the US or Canada, you meet it when a UK website, clinic, racing card or news story gives a weight like "11 st 4". This converter turns the pounds you know into the stone and pounds they use.
What Pounds to Stone Conversion Measures
This tool changes the unit, not the weight. 154 lb and 11 st 0 lb are the same weight written two ways. It does not judge your weight.
The Formula
UK weights and measures law lists the stone as 14 pounds¹. NIST's table of British units says the same², and both give the pound as exactly 0.45359237 kg¹ ².
Stone = whole number of (pounds / 14)
Pounds left over = pounds - 14 x stone
Decimal stone = pounds / 14
Kilograms = pounds x 0.45359237
How This Calculator Computes Your Result
Type your weight in pounds. Decimals are fine. The tool rounds your pounds to 0.1 lb (or to a whole pound, if you choose), and only then splits them into stone and pounds. This order matters. Take 153.96 lb. Split first, and you get 10 st and 13.96 lb, which rounds to the impossible "10 st 14 lb". Round first, and 153.96 becomes 154.0 lb, which is 11 st 0 lb. The pounds left over can never reach 14.
Decimal stone shows 2 decimals and kilograms show 1 decimal. Both come from your original number, so they can differ by 0.1 kg from a hand calculation on the rounded pounds.
What Your Result Means
Use this table to check a result quickly.
Pounds | Stone and pounds | Decimal stone | Kilograms |
70 | 5 st 0 lb | 5.00 | 31.8 |
80 | 5 st 10 lb | 5.71 | 36.3 |
90 | 6 st 6 lb | 6.43 | 40.8 |
100 | 7 st 2 lb | 7.14 | 45.4 |
110 | 7 st 12 lb | 7.86 | 49.9 |
120 | 8 st 8 lb | 8.57 | 54.4 |
130 | 9 st 4 lb | 9.29 | 59.0 |
140 | 10 st 0 lb | 10.00 | 63.5 |
150 | 10 st 10 lb | 10.71 | 68.0 |
160 | 11 st 6 lb | 11.43 | 72.6 |
170 | 12 st 2 lb | 12.14 | 77.1 |
180 | 12 st 12 lb | 12.86 | 81.6 |
190 | 13 st 8 lb | 13.57 | 86.2 |
200 | 14 st 4 lb | 14.29 | 90.7 |
225 | 16 st 1 lb | 16.07 | 102.1 |
250 | 17 st 12 lb | 17.86 | 113.4 |
275 | 19 st 9 lb | 19.64 | 124.7 |
300 | 21 st 6 lb | 21.43 | 136.1 |
350 | 25 st 0 lb | 25.00 | 158.8 |
400 | 28 st 8 lb | 28.57 | 181.4 |
A quick sanity check: the pounds part must be between 0 and 13.9. A decimal of .5 stone is 7 lb, and 1 stone is about 6.35 kg.
Dividing by 14 in Your Head
Count how many 14s fit into your weight, then see what is left. Anchors to remember: 140 lb is 10 st, 154 lb is 11 st, 168 lb is 12 st, 182 lb is 13 st, 196 lb is 14 st and 210 lb is 15 st.
For 187 lb, start at 182 (13 st). The leftover is 187 - 182 = 5. So 187 lb is 13 st 5 lb. If you have a kilogram weight, divide by 6.35 for a rough stone figure.
Why UK Weights Come in Stone
The stone began as a local rock used as a weight standard. Its size varied from 4 to 32 pounds, depending on the goods and the region. A 1389 statute set the stone of wool at 14 pounds, and 14 stuck³. Today it is still common in Britain for the weight of people³.
In UK law the stone sits in a list of units that may not be used for trade except as supplementary indications¹. You will not buy flour by the stone, but you will still hear body weight in stone.
Where You Will See Stone
Health news uses it. A 2021 Public Health England release said users of the NHS Weight Loss Plan app lost "almost a stone (5.8kg)" on average over 12 weeks⁴. In pounds, 5.8 kg is 12.8 lb, so "almost a stone" means 0 st 12.8 lb. The same release said adults who put on weight during lockdown gained 4.1 kg on average, about 9 lb, or just over half a stone⁴.
Horse racing uses it too. British handicap weights are given in stones and pounds, and a top weight of 9-7 means 9 st 7 lb, or 133 lb⁵. In boxing, the 160 lb middleweight limit is 11 st 6 lb and the 168 lb super middleweight limit is 12 st⁶.
A Note on Accuracy
The conversion is exact, because both 14 and 0.45359237 are defined values. Only the display is rounded. A bathroom scale can be off by a pound or more, and body weight changes through the day, so treat the answer as only as precise as your starting number.
Frequently Asked Questions
How many stone is 150 pounds?
150 pounds is 10 stone 10 pounds, or 10.71 stone. That is 68.0 kg.
How do you convert pounds to stone and pounds?
Divide the pounds by 14. The whole number is the stone, and the pounds left over after 14 x stone are the pounds. For 187 lb, that is 13 st and 5 lb.
Is a stone always 14 pounds?
Today, yes. In the past the stone ranged from 4 to 32 pounds depending on the goods, but the modern British stone is 14 pounds¹ ³.
Is this converter accurate?
Yes. It uses the exact factors from UK law and NIST¹ ², and rounds only at the end. Any error comes from the scale or the weight you enter.
Sources
Weights and Measures Act 1985, Schedule 1, UK Parliament
Handbook 44, Appendix C: General Tables of Units of Measurement, NIST, 2026
Stone (unit of weight), Encyclopaedia Britannica
Campaign launched to help public get healthy this summer, Public Health England, 2021
How handicap weights are determined, British Horseracing Authority
Weight divisions, BoxRec