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
  • No registration required
  • Works on all devices
Source
World Health Organization
Last updated
13-09-2026
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.

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, checked 13-09-2026.

Page last updated 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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