The short answer: 23 stones comes to 146.0567431 kg. That is 23 multiplied by 6.35029318, the factor fixed by definition, carried to full precision before anything is rounded for display.
At 146.057 kg, BMI works out to 57.1 at 1.60 m, 50.5 at 1.70 m, 45.1 at 1.80 m and 40.5 at 1.90 m. The healthy band tops out at 25, so the same weight can sit in three different categories depending on height — which is the whole limitation of the index.
The result sits 3.943 kg short of 150 kg, so if you need a round figure to quote, 150 kg is the honest nearest one. Plenty of people do this in their head: multiply by 6.4 instead of using the exact factor 6.35029318. At 23 that shortcut gives 147.2 kilograms, off by 1.143 kilograms or about 0.78%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
The formula
23 st- The quantity being converted
6.35029318- Exact kilograms in one stone
146.0567431 kg- The converted result
How it works, step by step
- Begin from the figure you have: 23 stones.
- Scale it by 6.35029318 — that is how many kilograms fit in a single stone.
- The product is 146.05674314 kilograms.
- To reverse it, divide by 6.35029318 instead: 146.0567431 kg ÷ 6.35029318 returns 23 st.
Worked examples
Step by step
Because this is a straight proportion, 23 st × 6.35029318 = 146.05674314 kg — no offset, no second term, nothing else to account for.
Proving it both ways
Run it in reverse — 146.0567431 kg ÷ 6.35029318 = 23 st. Matching the input you started from is the proof the direction is right.
How to read your score
Frequently asked questions
What is 23 stones in kilograms?
It comes to 146.0567431 kg. The unrounded figure is 146.05674314 kilograms, if you need to carry it forward.
How do you convert stones to kilograms?
Multiply by 6.35029318. So 23 × 6.35029318 = 146.0567431 kilograms. The factor comes from a definition rather than a measurement, so it never changes.
What is 146.0567431 kilograms back in stones?
Divide by 6.35029318, or multiply by 0.1574730444 — either returns 23 stones.
How much is 23 st in practice?
At 146.057 kg, BMI works out to 57.1 at 1.60 m, 50.5 at 1.70 m, 45.1 at 1.80 m and 40.5 at 1.90 m. The healthy band tops out at 25, so the same weight can sit in three different categories depending on height — which is the whole limitation of the index. The table lower down places it beside its neighbours so you can see where it sits.
What is a stone?
Fourteen pounds — still the customary way to state body weight in the UK and Ireland.
What is a kilogram?
The SI base unit of mass, redefined in 2019 in terms of the Planck constant.
23 st in kilograms — nearby values
| Stones | Kilograms | Unrounded |
|---|---|---|
| 17 st | 107.95498 | 107.9549841 |
| 18 st | 114.30528 | 114.3052772 |
| 19 st | 120.65557 | 120.6555704 |
| 20 st | 127.00586 | 127.0058636 |
| 21 st | 133.35616 | 133.3561568 |
| 22 st | 139.70645 | 139.70645 |
| 23 st | 146.05674 | 146.0567431 |
| 24 st | 152.40704 | 152.4070363 |
| 25 st | 158.75733 | 158.7573295 |
| 26 st | 165.10762 | 165.1076227 |
| 27 st | 171.45792 | 171.4579159 |
| 28 st | 177.80821 | 177.808209 |
| 29 st | 184.1585 | 184.1585022 |
Exact factor: 1 stone = 6.35029318 kilograms. The row for 23 st is the value this page is about.