Body mass index (BMI) is a quick screening number that relates weight to height. This calculator shows your BMI, the World Health Organization category it falls in, and the weight range that counts as healthy for your height. Your height and weight are health information, so they are never sent anywhere.
How to use
- Choose metric (cm, kg) or imperial (ft, in, lb).
- Enter your height and weight.
- Read your BMI, your category and your healthy weight range.
Why this tool is safe
This page loads no tracking scripts, and its security policy forbids it from sending data to other servers. The work happens in your browser's memory and is gone when you close the tab.
Frequently asked questions
How is BMI calculated?
BMI = weight in kilograms รท (height in metres)ยฒ. For example, 70 kg at 1.75 m gives 70 รท 3.0625 = 22.9.
What are the BMI categories?
For adults (WHO): under 18.5 underweight, 18.5โ24.9 normal weight, 25โ29.9 overweight, 30โ34.9 obesity class I, 35โ39.9 class II, and 40 or more class III.
Is BMI accurate for everyone?
No. BMI does not distinguish muscle from fat, and it is not meant for children, teenagers, pregnant women or very muscular people. It is a screening tool, not a diagnosis. For a real assessment of your health, talk to a doctor.