⚖️ BMI Calculator
Work out your Body Mass Index in stone, pounds and feet.
How it works
- BMI is your weight in kilograms divided by height in metres squared (kg/m²).
- NHS adult categories are roughly: under 18.5 underweight, 18.5-24.9 healthy, 25-29.9 overweight, and 30+ obese.
- We also show a healthy weight range for your height using BMI 18.5 to 24.9.
Common questions
Is BMI accurate for everyone?
BMI does not measure body fat directly. Athletes with high muscle may score higher BMI while still being lean. It is a screening tool, not a diagnosis.
Can I use stone and pounds?
Yes. Enter stone and pounds (or kilograms) and feet and inches (or centimetres). We convert behind the scenes using UK-friendly units.
What should I do next?
If your BMI is outside the healthy range, speak to your GP or try our healthy weight and waist to height tools for extra context.