Weight converter
Convert weight between metric (kg) and UK units (st/lb). Enter either format and press Calculate.
Tip: You only need to fill in one format (kg or st/lb).
Results
These are estimates based on your inputs.
How this calculator works
We use standard conversions: 1 stone = 14 lb and 1 lb = 0.453592 kg. Results may vary slightly due to rounding.
What this calculator does
This weight converter switches between kilograms (kg) and UK stone/pounds (st/lb). Enter either format and the calculator converts to the other so you can compare labels, medical forms, or fitness targets.
It is ideal for quick conversions between metric and UK units without manual maths.
How the formula works
We use standard conversions: 1 stone equals 14 pounds, and 1 pound equals 0.453592 kilograms. We convert to a base unit then format the output for the other system.
Results are rounded, so small differences can appear when converting back and forth.
Worked example
Example: 72 kg converts to about 11 st 5 lb. If you enter 11 st 5 lb, the calculator returns roughly 72 kg.
A small rounding difference is normal when converting between units.
Common mistakes
- Entering pounds in the stone field.
- Using stones with decimals instead of separate pounds.
- Leaving both kg and st/lb blank.
- Assuming exact reversibility after rounding.
When to use this calculator
Use this when converting between UK and metric units for health, fitness, or paperwork. If you need height conversions too, use the Height converter alongside this.
FAQs
How many kg in a stone?
One stone is 14 pounds, which is about 6.35029 kg.
Why does my result look different to another calculator?
Small differences usually come from rounding rules or the number of decimal places used.
Can I enter decimals in stones?
You can, but the most common UK format is stones and pounds separately. Use the pounds field for accuracy.