BMI Prime turns BMI into a simple ratio that is easy to interpret as a percentage above or below the healthy upper limit.
How to use the BMI Prime Calculator
- Weight
- Height
Results update as you type, and every field accepts the units shown in its menu.
How it works
Calculate BMI from weight and height, then divide by 25.
Inputs explained
| Field | What to enter |
|---|---|
| Weight | Units: kg, lb, g, oz, st |
| Height | Units: cm, m, mm, in, ft |
What each result means
- BMI = [Weight]÷([Height]÷100)^2
- BMI Prime = [BMI]÷25
Example values
How the main result changes when Weight changes and everything else stays at the example values above:
| Weight (kg) | BMI Prime |
|---|---|
| 41 | 0.54 |
| 61.5 | 0.8 |
| 82 | 1.07 |
| 102.5 | 1.34 |
| 123 | 1.61 |
| 164 | 2.14 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
BMI Prime = BMI ÷ 25Worked example
Inputs — Weight: 82 kg; Height: 175 cm.
Results — BMI = 26.8; BMI Prime = 1.07.
Frequently asked questions
What does 1.07 mean?
Your BMI is 7% above the healthy upper limit of 25.
Can I use a different limit?
Some Asian guidelines use 23 as the upper limit.
What formula does the BMI Prime Calculator use?
BMI Prime = BMI ÷ 25.