Quick Answer: Stones to Kilograms
One stone is approximately 6.35 kilograms (1 st ≈ 6.35 kg).
Conversely, 1 kg ≈ 0.1575 st.
Formula: kg = st × 6.35029318
Worked examples
- 1 st ≈ 6.35 kg
- 5 st ≈ 31.75 kg
- 8 st ≈ 50.8 kg
Method and limitations
Multiply stones by 6.35029318 (14 lb × 0.45359237 kg per lb). Calculations use full-precision constants; answers in this box are rounded for readability (≈ marks a rounded value) and the calculator shows up to 9 significant figures. A stone is exactly 14 avoirdupois pounds (6.35029318 kg). Body weights are usually written as stones plus pounds (11 st 4 lb = 158 lb), which is not the same as decimal stones (11.4 st = 11 st 5.6 lb).
Each factor is exact by definition, derived from exact definitions, or a documented conventional value — see the methodology and sources.
Conversion Formula
Multiply stones by 6.35029318 (14 lb × 0.45359237 kg per lb).
Complete Guide to Stones to Kilograms Conversion
What is a stone?
The stone (st) is 14 avoirdupois pounds, exactly 6.35029318 kg. Weights are written as stones plus pounds, e.g. 11 st 4 lb.
What is a kilogram?
The kilogram (kg) is the SI base unit of mass.
How the Conversion Works
kg = st × 6.35029318. The calculator takes decimal stones; for stones and pounds use (st × 14 + lb) × 0.45359237, or divide the pounds by 14 and add them to the stones.
Step-by-Step Conversion Guide
Follow these steps to convert stones to kilograms manually:
Start with your value in stones
Example: You want to convert 8 st
Apply the conversion formula
Use the formula: kg = st × 6.35029318
Calculate the result
8 st = 50.8023 kg
Verify your answer
Use our calculator above to double-check your manual calculation.
Quick Mental Math Tip
Multiply by 6.35: 10 st ≈ 63.5 kg. For stones and pounds, convert to total pounds first.
Common Conversions
| Stones (st) | Kilograms (kg) | Kilograms → Stones |
|---|---|---|
| 1 st | 6.35029 | 1 kg = 0.157473 st |
| 5 st | 31.7515 | 5 kg = 0.787365 st |
| 8 st | 50.8023 | 8 kg = 1.25978 st |
| 10 st | 63.5029 | 10 kg = 1.57473 st |
| 11 st | 69.8532 | 11 kg = 1.7322 st |
| 12 st | 76.2035 | 12 kg = 1.88968 st |
| 13 st | 82.5538 | 13 kg = 2.04715 st |
| 14 st | 88.9041 | 14 kg = 2.20462 st |
| 15 st | 95.2544 | 15 kg = 2.3621 st |
| 20 st | 127.006 | 20 kg = 3.14946 st |
Popular Stones to Kilograms Conversions
Tap any value to load it into the calculator above.
When You'll Need This Conversion
UK and Irish body weights
Give a weight written in stones and pounds in kilograms.
Common Mistakes to Avoid
Reading 11 st 4 lb as 11.4 st
The pounds part is out of 14, not 10.
11 st 4 lb = 11.286 st = 71.67 kg.
Frequently Asked Questions
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Conversion factors on this page are either exact by definition, derived from exact definitions, or conventional values in documented use. Each is listed with its source in our conversion methodology and sources, which cites the BIPM SI Brochure, NIST Special Publication 811 and the relevant IEC or national standards. Results are rounded for display only; calculations use full precision.