Free health tool

BMI, with the context most calculators leave out.

Calculate your adult BMI in under a minute. Compare the global reference with South Asian guidance, then choose whether you want a more personal next step.

Your number appears before we ask for contact details.

The calculation happens in your browser and is not saved unless you request the detailed view.

Step 1

Enter your measurements

Where you live

Units

Family background (optional)

Health risk can start at a lower weight for some backgrounds, so UK and WHO guidance uses lower BMI cut-offs. We only use this to pick the right range.

Height (cm)

Weight (kg)

I confirm I am 18 or older. This adult BMI tool is not intended for children or pregnancy.

Your measurements stay in your browser until you request details.

Step 2

Your result will appear here.

You will see the number first, read against the right range for your background. No email is needed to calculate it.

BMI is one screening measure. It cannot describe body composition, fitness or overall health on its own.

Read your result carefully

Useful screening. Not a diagnosis.

BMI compares weight with height. It does not measure muscle, body-fat distribution, nutrition quality or fitness. It may be less informative during pregnancy, for older adults, highly muscular people and some health conditions.

Reference ranges used

WHO global: underweight below 18.5; healthy 18.5–24.9; overweight 25–29.9; obesity from 30.
Lower cut-offs (NICE, UK): for South Asian, East Asian, Middle Eastern and Black family backgrounds. Healthy 18.5–22.9; increased risk 23–27.4; higher risk from 27.5.

WHO reference WHO expert consultation NICE guidance All sources

References reviewed October 2026. Not suitable during pregnancy or breastfeeding, for children, or if you have an eating disorder. If you have symptoms or medical concerns, speak with your doctor.