About this tool
Work out your body mass index (BMI) from your weight and height in kilograms and centimetres, or pounds, feet and inches. You'll see your BMI, the adult category it falls into using World Health Organization ranges, and the healthy weight range for your height.
How to use it
- Choose metric or imperial units.
- Enter your weight and height.
- Read your BMI, category and healthy weight range.
Good to know
- Categories use WHO adult ranges: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30 and above obesity.
- BMI doesn't distinguish muscle from fat and isn't designed for children, pregnancy or athletes.
- This is general information, not medical advice — speak to a doctor about your health.
Frequently asked questions
How is BMI calculated?
BMI is your weight in kilograms divided by your height in metres squared. Imperial measurements are converted to metric first.
Is BMI accurate for everyone?
It's a quick screening measure for adults. Very muscular people can have a high BMI without excess fat, so it shouldn't be used alone.