How many pounds are in a stone?

There are exactly 14 pounds in one stone. This has been fixed since the Weights and Measures Act of 1835 standardised the stone at 14 pounds for general trade.

How do I convert kg to stone?

Divide the kilograms by 6.35029. For example, 70 kg ÷ 6.35029 = 11.02 stone, which is 11 stone 0.3 pounds. To get the pounds part, multiply the decimal remainder by 14.

How many kilos is 10 stone?

10 stone is 63.5 kg, or 140 pounds. Multiply the number of stone by 6.35029 to get kilograms.

Why is the stone still used in the UK?

The stone remains the customary way to state body weight in the UK and Ireland even though medical records and scales are metric. It survives in everyday speech rather than in trade, where metric units are required.

How Many Kg in a Stone? (1 Stone = 6.35 kg)

Q: How many kg in a stone?

One stone equals 6.35029318 kilograms, usually rounded to 6.35 kg. The stone is defined as exactly 14 pounds, and one pound is exactly 0.45359237 kg, so the conversion is exact rather than approximate.

The stone is a unit of mass in the British imperial system, used almost entirely for body weight in the UK and Ireland. Unlike many older units, its modern value is not an approximation: the stone is defined as exactly 14 pounds, and since 1959 the international pound has been defined as exactly 0.45359237 kilograms. Multiply those together and you get 6.35029318 kg, exactly.

The Exact Conversion

1 stone = 14 lb

1 lb = 0.45359237 kg (exact, by international agreement)

1 stone = 14 × 0.45359237 = 6.35029318 kg

In everyday use this is rounded to 6.35 kg, which is accurate to well within the precision of any bathroom scale. Going the other way, one kilogram is 0.157473 stone — a number few people memorise, which is why converting kg to stone is nearly always done with a chart or a kg to stone calculator.

Stone to Kilograms Chart

Stone	Pounds	Kilograms
1 st	14 lb	6.35 kg
2 st	28 lb	12.70 kg
3 st	42 lb	19.05 kg
4 st	56 lb	25.40 kg
5 st	70 lb	31.75 kg
6 st	84 lb	38.10 kg
7 st	98 lb	44.45 kg
8 st	112 lb	50.80 kg
9 st	126 lb	57.15 kg
10 st	140 lb	63.50 kg
11 st	154 lb	69.85 kg
12 st	168 lb	76.20 kg
13 st	182 lb	82.55 kg
14 st	196 lb	88.90 kg
15 st	210 lb	95.25 kg
16 st	224 lb	101.60 kg
17 st	238 lb	107.95 kg
18 st	252 lb	114.31 kg
19 st	266 lb	120.66 kg
20 st	280 lb	127.01 kg

Converting Kg to Stone and Pounds

Most people want the answer in the two-part form used on UK scales — "11 stone 4" rather than "11.29 stone". That takes one extra step:

Divide the kilograms by 6.35029 to get decimal stone.
Take the whole number — that is your stone.
Multiply what is left after the decimal point by 14 — that is your pounds.

Example: 72 kg

72 ÷ 6.35029 = 11.338 stone

0.338 × 14 = 4.7 lb

72 kg = 11 stone 4.7 lb

How Many Pounds in a Stone?

Exactly 14, and it has been since the Weights and Measures Act of 1835 fixed the stone at 14 pounds for general trade. Before that the stone varied by commodity — wool, meat and cheese each had their own stone, ranging from about 8 to 24 pounds. The single 14-pound stone we use today is what remains of that older system. You can convert in either direction with the pounds to stone calculator or the stone to pounds converter.

Common Conversions at a Glance

Question	Answer
How many kg in a stone?	6.35 kg
How many pounds in a stone?	14 lb
How many kg is 10 stone?	63.50 kg
How many kg is 12 stone?	76.20 kg
How many stone is 100 kg?	15 st 10.5 lb
How many stone is 80 kg?	12 st 8.4 lb

Sources

NIST Special Publication 811: Guide for the Use of the International System of Units — the source of the exact pound-to-kilogram factor used above.
Weights, measures and packaging: the law — GOV.UK — current UK rules on units of measurement.

Reviewed by the Stone Calculator editorial team · Last updated July 28, 2026