BMI calculator (metric and imperial)
Calculate Body Mass Index from height and weight, with the WHO category and a healthy-weight range.
- Runs in your browser
- Nothing uploaded
- Works offline
- No sign-up
About this tool
Enter your height and weight in metric or imperial units to get your Body Mass Index, the World Health Organization category it falls into (underweight, normal, overweight, obese), and the weight range that would put you in the "normal" band for your height. BMI is a rough screening number, not a diagnosis - it does not account for muscle, build or age.
How to use it
- Choose metric (cm / kg) or imperial (ft-in / lb).
- Enter your height and weight.
- Read your BMI, its category, and the healthy-weight range for your height.
Frequently asked questions
How is BMI calculated?
Weight in kilograms divided by height in metres squared (kg/m2). Imperial inputs are converted first.
Is BMI accurate for everyone?
No. It is a population-level screening tool. Very muscular people can read as "overweight" and it is less reliable for children, older adults and some ethnic groups.
Is this medical advice?
No - it is an informational calculator. Talk to a health professional about your individual situation.
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