Height and weight go in, one number comes out: the body mass index, your weight in kilograms divided by your height in meters squared. This BMI calculator works with metric and imperial units, names your WHO category, and shows the range of weights that count as healthy for your height, plus how far you are from it. A colored scale marks where your value sits.
Find your BMI in three steps
- Choose metric (centimeters and kilograms) or imperial (feet, inches and pounds).
- Enter your height and your weight. Decimals and a decimal comma both work.
- Read the BMI, the category, the healthy weight range and the difference, and look at the marker on the scale.
The WHO categories for adults
- Below 18.5: underweight.
- 18.5 to 24.9: normal weight.
- 25 to 29.9: overweight.
- 30 to 34.9: obesity class I, 35 to 39.9 class II, and 40 or more class III.
How to read the result
A BMI of 22.9 is the same for a person of 175 cm and 70 kg and for one of 160 cm and 58.6 kg, which shows why the healthy range depends on height. The calculator gives that range in kilograms or pounds, so you can see a concrete target. A value just outside a limit is not a sudden change in health: the limits are conventions, and a few tenths of a point mean little.
What BMI cannot tell you
BMI looks only at height and weight. It cannot separate muscle from fat, so a strong athlete can land in the overweight class, and it ignores where fat sits on the body. It is not meant for children and teenagers, who use age-based charts, nor for pregnancy. Some health bodies suggest lower limits for people of Asian descent. Treat it as a screening number and talk to a doctor about your health.
Private by design
Your height and weight are calculated in your browser and never sent or stored.