Relative Fat Mass (RFM) Calculator

The Relative Fat Mass (RFM) is a validated body composition index developed by Woolcott and Bergman (2018) as an accurate predictor of whole-body fat percentage, outperforming traditional body mass index (BMI) in estimating adiposity. RFM is calculated from waist circumference and height measurements without requiring expensive dual-energy X-ray absorptiometry (DXA) or bioelectrical impedance: RFM = 64 – (20 × Height/Waist) [men] or RFM = 76 – (20 × Height/Waist) [women]. Unlike BMI (which does not distinguish fat from lean body mass), RFM correlates strongly with DXA-measured body fat percentage (r² = 0.73 in men, 0.82 in women) and predicts visceral adiposity and cardiometabolic risk more accurately.