Calculate your Body Mass Index in metric or imperial units and see your weight category instantly.
Anyone checking whether their weight is in a healthy range for their height.
Choose your units
Switch between metric (cm, kg) and imperial (ft/in, lb).
Enter height and weight
Type your measurements into the fields.
Read your category
Your BMI and weight category appear instantly, colour-coded against WHO ranges.
Body Mass Index is a quick screening tool used by health services worldwide to flag whether weight may be too low or too high for a given height. It is easy to miscalculate by mixing units — this tool handles both metric and imperial correctly.
Health check-ins
Track whether your weight sits in the healthy range over time.
Fitness goals
Use BMI as one reference point alongside other measures when setting targets.
Medical forms
Quickly compute BMI when a form or doctor asks for it.
The WHO ranges are: under 18.5 underweight, 18.5–25 normal, 25–30 overweight, 30+ obese.
BMI is a screening tool, not a diagnosis. It does not distinguish muscle from fat, so very muscular people may read high. Consult a professional for personalised advice.
No. The calculation runs entirely in your browser.