BMI calculator

Enter your height and weight to see your body mass index (BMI) and the standard adult category. Switch units to use feet and pounds

How it works

Worked example

How to read your result

A person who is 170 cm tall and weighs 70 kg has a BMI of 70 ÷ (1.70 × 1.70) = 24.2, which is in the healthy weight range.

BMI is your weight in kilograms divided by your height in metres, squared. The imperial version uses 703 × pounds ÷ inches squared.

Can I use this for children?

No, children need BMI-for-age charts.

Does BMI measure body fat?

Not directly.

Should I see a doctor about my result?

If you’re worried, speak to your GP or a qualified professional.

Frequently asked questions

Adults: under 18.5 is underweight, 18.5 to 24.9 healthy weight, 25 to 29.9 overweight, and 30 or more obesity. BMI doesn’t distinguish muscle from fat, or account for age, sex or ethnicity, so treat it as a rough guide, not a diagnosis.