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Calculate body mass index in metric or imperial units with categories.
BMI, or body mass index, is a number calculated from weight and height: weight in kilograms divided by height in metres squared. It gives a rough position within the standard underweight, normal, overweight, and obesity ranges used by public health organizations.
The calculator accepts metric or imperial units and shows the category band alongside the number. Your measurements are processed in your browser and are never uploaded or stored.
Metric
Input
175 cm, 68 kgOutput
BMI 22.2 - normal weight range (18.5 to 24.9)1.75 metres squared is 3.0625, and 68 divided by 3.0625 is 22.2.
Imperial
Input
5 ft 9 in, 150 lbOutput
BMI 22.1 - normal weight range (18.5 to 24.9)69 inches squared is 4,761, and 703 times 150 divided by 4,761 gives 22.1.
Under 18.5 is underweight, 18.5 to 24.9 is normal, 25 to 29.9 is overweight, and 30 or above is obese. These are screening bands, not diagnoses.
Rounding, the time of day you weighed yourself, and differences in height measurement can all shift the result slightly. The formula itself is the same everywhere.
BMI is a rough screening figure and does not account for muscle mass, age, or body composition, so treat it as informational rather than medical advice.
No. The calculation happens in your browser and nothing you enter is transmitted or saved.
BMI
—
Enter your height and weight.
Category
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Shown once height and weight are valid
This is a general informational calculator, not medical advice. Consult a professional for health guidance.