BMI Calculator
Metric or imperial — BMI and category, live. One rough signal, not a diagnosis.
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Calculated on your device — nothing is stored or sent.
Common questions
How is BMI calculated?
Weight in kilograms divided by height in meters squared. The imperial mode converts pounds and feet/inches for you — same formula underneath.
What do the BMI categories mean?
The WHO ranges: under 18.5 underweight, 18.5–24.9 the healthy range, 25–29.9 overweight, 30+ obese. They're population-level screening bands, not diagnoses.
What are BMI's limitations?
It can't tell muscle from fat — athletes routinely score "overweight" while lean — and it ignores where weight sits, which matters more for health. Treat it as one rough signal among many, and treat your doctor as the authority.