BMI Calculator
Body Mass Index for adults using metric or US units, with category and healthy weight range.
BMI
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Category
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BMI Prime
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Healthy Weight Range
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1020304050
Waist-to-Height Ratio (optional)
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A waist-to-height ratio under 0.5 is often cited as lower cardiometabolic risk for adults. This does not replace medical guidance.
BMI Categories
| Category | BMI (kg/m²) |
|---|---|
| Underweight | < 18.5 |
| Normal weight | 18.5 – 24.9 |
| Overweight | 25.0 – 29.9 |
| Obesity class I | 30.0 – 34.9 |
| Obesity class II | 35.0 – 39.9 |
| Obesity class III | ≥ 40.0 |
For athletes, children/teens, older adults, and during pregnancy, BMI may misclassify. Use additional measures and professional advice.