BMI Prime Calculator

Calculate your BMI Prime — the ratio of your BMI to the upper limit of the normal BMI range (25) — from your weight and height.

  • Free to use
  • Accurate results
  • No registration required
  • Works on all devices
Enter your weight and height to get your BMI Prime — your BMI divided by 25.
kg
cm

Your result

0.97

BMI Prime

AI explanation

Formula

BMI Prime = BMI / 25

Worked example

70kg, 170cm

Worked example: 70kg, 170cm
FieldValue
Weight70
Height170
BMI Prime0.97

Assumptions

  • BMI Prime expresses BMI as a ratio to the WHO upper-normal cutoff of 25; a value of 1.0 means BMI is exactly at that cutoff.
  • Informational only — not a diagnosis.

Frequently asked questions

What is BMI Prime?

BMI Prime is your BMI divided by 25 (the upper limit of the WHO normal BMI range). A value under 1.0 means your BMI is below that cutoff; over 1.0 means it's above.

How is BMI Prime different from BMI?

BMI is measured in kg/m². BMI Prime is a unitless ratio that makes it easy to see, at a glance, how far above or below the normal-range cutoff someone's BMI falls — a BMI Prime of 1.20 means BMI is 20% above the cutoff.

What is a healthy BMI Prime range?

Roughly 0.74 to 1.00 corresponds to the WHO normal BMI range of 18.5-25.

Related calculators

BMI CalculatorHealthy Weight Calculator

Sources

  • Body mass index — World Health Organization. Effective 01-01-1995, reviewed 13-09-2026.

This calculator provides a general estimate only and does not constitute personalized medical advice. Consult a qualified healthcare professional for a full health assessment.

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