BMI Calculator — Free Body Mass Index Calculator

Calculate your Body Mass Index from your height and weight in seconds. Supports metric and imperial — free, no signup.

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Frequently Asked Questions

Is BMI an accurate measure of health?
BMI is a useful screening tool but does not account for muscle mass, bone density, or body composition. Athletes and very muscular people, for example, may show a higher BMI without excess body fat. It is best used as a general guideline, not a diagnosis.
What do the BMI categories mean?
Under 18.5 is considered underweight, 18.5-24.9 is the typical range, 25-29.9 is overweight, and 30+ falls into the obese category, per WHO standard classifications.