BMI Calculator
Body mass index estimates whether your weight is in a healthy range for your height. Type in your height and weight to see your BMI and its WHO band. This is a screening aid, not medical advice.
How it works
Enter your height in centimetres and your weight in kilograms. Your BMI and weight band appear right away — nothing is saved or sent anywhere.
Formula and source
BMI = weight (kg) ÷ height (m)². Bands: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30+ obesity. Source: World Health Organization.
Worked examples
- 70 kg at 170 cm ? BMI 24.2 — healthy range
- 90 kg at 170 cm ? BMI 31.1 — obesity range
Tips
- Measure height without shoes for an accurate result.
- BMI does not distinguish muscle from fat — athletes may read high.
- Track the trend over weeks, not single readings.
FAQ
What is a healthy BMI?
The WHO defines 18.5u201324.9 as the healthy range for most adults.
How is BMI calculated?
Divide weight in kilograms by height in metres squared.
Is BMI accurate for muscular people?
Not always u2014 muscle weighs more than fat, so very muscular people can score as overweight despite low body fat.
Does BMI work for children?
Children use BMI-for-age percentiles, not adult bands u2014 ask a paediatrician.
Is the BMI calculator free?
Yes, completely free with no signup.
Is my data stored?
No. All calculations happen locally in your browser.