Health & Fitness

BMI Prime Calculator

Express BMI as a ratio to the upper healthy limit of 25, so 1.0 marks that boundary.

The result rescales BMI against the 25 boundary, so a value below 1.0 means the BMI sits under that boundary, while a value of exactly 1.0 would sit on it and a value above 1.0 would sit over it.

Formula

BMI Prime equals BMI divided by 25, the upper end of the usual healthy BMI range.

How it works

The page first works out BMI from weight and height, then divides it by 25. A value of 1.0 sits exactly on that boundary, below 1.0 is under it, and above 1.0 is over it.

Worked example

For example, a weight of 70 kg and a height of 175 cm gives a BMI of 22.86, and 22.86 divided by 25 equals 0.91, so the BMI Prime is 0.91 (shown with a BMI of 22.9).

FAQs

Is BMI Prime better than BMI?
It is the same information rescaled, so it adds clarity, not new accuracy.

What does 1.0 mean?
It means a BMI of 25, the top of the usual healthy range.

Does it work for athletes?
No better than BMI itself; muscle still raises the number.

General information only, not medical advice.

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