BMI Calculator

Calculate your Body Mass Index (BMI) using metric or imperial units, with healthy weight ranges and category. Free, private BMI calculator.

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BMI calculator (metric & imperial)

Calculate your Body Mass Index from your height and weight in either metric or imperial units. You'll see your BMI value, the category it falls in, and the healthy weight range for your height. Calculations run privately in your browser.

Frequently asked questions

How is BMI calculated?

BMI = weight (kg) ÷ height (m)². In imperial units it's 703 × weight (lb) ÷ height (in)². It estimates body fat from height and weight.

What are the BMI categories?

Under 18.5 is underweight, 18.5–24.9 is a healthy weight, 25–29.9 is overweight, and 30 or above is in the obese range (adult guidelines).

Is BMI accurate for everyone?

BMI is a useful general screen but doesn't distinguish muscle from fat, so it can misclassify athletes and others. Treat it as a starting point, not a diagnosis.