Relative Fat Mass Calculator
Estimate relative fat mass from height and waist circumference using sex-specific equations.
Relative Fat Mass measurements
Enter your values, then calculate.
Result
How to calculate relative fat mass
Estimate body-fat percentage using relative fat mass, a height-to-waist equation that does not require body weight.
How the calculation works
The equation divides height by waist circumference, multiplies the ratio by 20, then subtracts it from a sex-specific constant.
Example
For a man 178 cm tall with a 92 cm waist, RFM is approximately 25.3%.
Frequently asked questions
Is RFM the same as a clinical body-fat measurement?
No. It is a screening estimate and can differ from DEXA, air-displacement, or other measured methods.
Relative Fat Mass Calculator
The equation divides height by waist circumference, multiplies the ratio by 20, then subtracts it from a sex-specific constant.
Let's understand your relative fat mass result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Relative Fat Mass
- Measure waist at the recommended anatomical point with the tape level.
- Use the same units for height and waist.
Common Relative Fat Mass Mistakes to Avoid
- Mixing inches and centimeters changes the ratio and invalidates the result.
When to Use This Calculator
Estimate body-fat percentage using relative fat mass, a height-to-waist equation that does not require body weight.