BMI calculator

Enter your weight and height – see your BMI, the WHO category and your healthy weight range.

–BMI

WHO classification for adults. BMI is not a substitute for medical advice.

100% private: everything is processed locally in your browser. Your data never leaves your device.

How to use

  1. Enter your weight and height in kg/cm or switch to lb/ft.
  2. Your BMI and category appear instantly.
  3. Below you see the weight range that gives a healthy BMI for your height.

What does BMI tell you?

Body mass index is weight in kg divided by height in meters squared. The WHO classifies adults as follows: below 18.5 underweight, 18.5–24.9 healthy weight, 25–29.9 overweight, 30 and above obese.

BMI is only a rough guide. It doesn't distinguish between muscle and fat and isn't suitable for children, pregnant women or athletes. For a health assessment, talk to a doctor.

Frequently asked questions

How is BMI calculated?

BMI = weight (kg) ÷ height (m)². For 70 kg and 1.75 m that's 70 ÷ 3.0625 ≈ 22.9. In imperial units: 703 × weight (lb) ÷ height (in)².

Does BMI apply to children?

No. For children and teens, age- and sex-specific percentiles are used instead.

Is my data stored?

No. The calculation happens only in your browser and nothing is transmitted.