RFM Calculator – Relative Fat Mass
Estimate your body fat percentage with the Relative Fat Mass (RFM) formula, which uses only your height, waist circumference, and sex.
What is Relative Fat Mass (RFM)?
Relative Fat Mass is a body fat estimation formula developed as an alternative to BMI. Research published in 2018 found that RFM, which only needs height, waist circumference, and sex, correlated more closely with body fat measured by DEXA scans than BMI did in the study population.
How it is calculated
The formulas are: Men: RFM = 64 − (20 × height ÷ waist). Women: RFM = 76 − (20 × height ÷ waist). Height and waist must be entered in the same unit (both inches or both centimeters) since the ratio between them is what matters, not the specific unit.
RFM is a population-level statistical estimate, not a direct measurement of body fat, and individual results can vary from more precise methods like DEXA scanning or hydrostatic weighing. This tool is for general educational and planning purposes only.