BMI Prime
The ratio of your BMI to the upper normal limit (25). Below 1 is under, above 1 is over.
kg
cm
BMI Prime0.98
BMI24.5
CategoryNormal weight
BMI Prime = BMI / 25. A value of 1.0 sits exactly at the upper normal limit.
How it works
BMI Prime is a neat way to express body mass index as a simple ratio, showing at a glance how far you are from the upper limit of the healthy range.
It divides your BMI by 25, the top of the normal range set by the World Health Organization. A BMI of 25 gives a BMI Prime of exactly 1.0; a BMI of 30 gives 1.2, meaning 20% above the limit; and a BMI of 22 gives 0.88, comfortably inside the range.
Because it is a ratio around 1.0, BMI Prime makes it easy to compare people and to see the size of the gap to a healthy weight, rather than reading a raw BMI number.
Frequently asked questions
What is a healthy BMI Prime?
Between 0.74 and 1.00, which corresponds to a BMI of 18.5 to 25. Below 0.74 suggests underweight and above 1.00 suggests overweight.
Why use BMI Prime instead of BMI?
It expresses the same information as a ratio to the healthy limit, so a value of 1.2 instantly tells you that you are 20% over. Some people find that clearer than a plain BMI figure.
Is it better than BMI?
It is another way to express BMI, not a separate diagnosis.