BMI Prime Calculator
BMI Prime is a simple modification of BMI that expresses your BMI as a ratio of the upper limit of the normal BMI range (25 kg/m²). A BMI Prime below 0.74 is underweight; 0.74–1.0 is normal weight; 1.0–1.2 is overweight; above 1.2 is obese. It makes BMI results immediately interpretable — 1.0 is exactly at the healthy/overweight boundary.
How to Use This Calculator
- 1
Select metric or imperial units.
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Enter your weight and height.
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Click Calculate — a result below 1.0 means you're within or below the normal BMI range.
Frequently Asked Questions
BMI Prime of 1.0 means your BMI is exactly 25 — the upper boundary of the normal weight range. Below 1.0 is normal or underweight; above 1.0 is overweight or obese.