How to use it
- Choose kg / cm or lb / ft in.
- Enter your weight and height.
- Read your BMI, its category and the healthy weight range for your height.
Questions and answers
How is BMI calculated?
BMI is weight in kilograms divided by height in meters squared. For 70 kg and 1.70 m: 70 ÷ (1.70 × 1.70) = 24.2.
What is a healthy BMI?
For adults, the WHO considers 18.5 to 24.9 normal, 25 to 29.9 overweight and 30 or more obesity. BMI does not measure body fat directly, so very muscular people can score high.
Does it work for children or during pregnancy?
No. Children and teens are assessed with age- and sex-specific charts, and BMI is not used to judge weight in pregnancy. Ask a health professional in those cases.