Unit converter
Stone to Kilograms Converter
This tool turns a weight in stone into kilograms. One stone equals exactly 6.35029318 kilograms, because a stone is 14 pounds and the pound is fixed at 0.45359237 kg. In Britain and Ireland, body weight is still spoken of in stone, so the conversion comes up at the doctor, on the bathroom scales, and when a fitness app or gym chart wants the metric figure. Enter the stone value and the kilogram equivalent appears at once, alongside a short table covering the readings people check most.
1 stone = 6.3503 kilograms
Common stone to kilograms values
| Stone | Kilograms |
|---|---|
| 1 st | 6.3503 kg |
| 2 st | 12.7006 kg |
| 5 st | 31.7515 kg |
| 10 st | 63.5029 kg |
| 20 st | 127.01 kg |
| 50 st | 317.51 kg |
| 100 st | 635.03 kg |
How to convert
- Start with the weight written in stone.
- Multiply by 6.35029318 to reach kilograms, since fourteen pounds make one stone.
- If your weight is given as stone and pounds, change the pounds to a fraction of a stone first (divide pounds by 14) and add it on.
- Reverse the sum by dividing kilograms by 6.35029318 to recover stone.
- For a rough head count, six and a third kilograms per stone works: 10 st sits a touch above 63 kg.
kilograms = stone × 6.35029318
A stone holds fourteen pounds, and each pound is exactly 0.45359237 kg, so one stone is 14 times that, namely 6.35029318 kg. Multiplying a weight in stone by this constant gives kilograms; dividing kilograms by it returns to stone.
- st
- the weight in stone you begin with
- 6.35029318
- kilograms in one stone, by definition
Worked example
Someone who weighs 12 stone multiplies 12 by 6.35029318 and gets 76.2 kg. A reading of 11 stone 7 pounds becomes 11.5 stone, which is 11.5 times 6.35029318, or about 73.03 kg.
Key facts
- One stone is exactly 6.35029318 kg; one kilogram is about 0.1575 stone.
- Ten stone equals roughly 63.5 kg.
- A stone is fourteen pounds, a grouping unique to the imperial system.
- NHS records and most medical charts in Britain show both stone and kilograms.
Tips
- For a quick guess, add a sixth on top of six times the stone figure: 8 st is about 48 plus 2.5, near 50 kg.
- When logging weight in an app set to metric, convert once and store the kilogram value to avoid repeating the sum.
Frequently asked questions
How many kg in 1 stone?+
Exactly 6.35029318 kilograms. The value follows from 14 pounds at 0.45359237 kg each.
How do I deal with stone and pounds together?+
Convert the pounds part to stone by dividing by 14, add it to the whole stone, then multiply the total by 6.35029318.
Is stone used outside the UK?+
Rarely. Britain and Ireland keep it for body weight; most countries weigh people in kilograms, and the United States uses pounds alone.
Why does the scale at the gym differ from my home scale?+
Usually rounding or calibration, not the conversion. The stone-to-kilogram factor itself is exact and never varies.
Things to watch
- Do not confuse stone with the US practice of quoting pounds only; 200 lb is about 14.3 stone, not 200 stone.
- Rounding to whole kilograms can shift a reading by up to half a kilogram, which matters for medication dosing.
Sources
Last updated: 2026-01-01
Conversions use internationally defined factors. Provided for general use; verify critical measurements independently.