Relative Fat Mass (RFM) Studio — Cedars-Sinai Model
Calculate your estimated body fat percentage with the clinically validated Relative Fat Mass (RFM) formula! Formulated by Cedars-Sinai Medical Center using NHANES DEXA scan datasets, RFM evaluates abdominal waist-to-height proportions (\(64 - 20 \times \frac{\text{height}}{\text{waist}}\) for men, \(76 - 20 \times \frac{\text{height}}{\text{waist}}\) for women) to provide a superior adiposity indicator over standard BMI.
Demographics Console
Adjust your waist parameters to evaluate relative fat mass percentages instantly
Clinical Demographics Presets
Click average body benchmarks to sync metrics instantly
🔬 RFM vs. BMI vs. BAI Comparison
Understand how varying body composition models segment metabolic wellness risks
Relative Fat Mass (RFM)
Uses waist circumference relative to height. Strong scientific correlation to dual-energy X-ray absorptiometry (DXA) scans, successfully distinguishing muscular mass from fat mass.
Body Mass Index (BMI)
Measures weight relative to height. Frequently misclassifies muscular athletic physiques as overweight or obese, disregarding body composition and tissue density.
Body Adiposity Index (BAI)
Calculated utilizing hip circumferences relative to height. Tends to over-calculate body fat values for highly lean athletic profiles, though ideal for general sedentary diagnostics.
Cedars-Sinai Medical Equations
Formulas derived from NHANES clinical survey sets representing absolute fat thresholds
👨 Male Body Fat Equation
RFM = 64 - (20 × height cm / waist cm) 👩 Female Body Fat Equation
RFM = 76 - (20 × height cm / waist cm) BMI vs. BMR vs. TDEE — What's the Difference?
Demystify your body metrics. Learn how Basal Metabolic Rate, Body Mass Index, and Daily Expenditure interlink with advanced measurements like RFM and WHR to shape your fitness blueprint.
Read the Complete Guide➝
Overview & Capabilities
Calculate your estimated body fat percentage with the clinically validated Relative Fat Mass (RFM) formula! Formulated by Cedars-Sinai Medical Center using NHANES DEXA scan datasets, RFM evaluates abdominal waist-to-height proportions (\(64 - 20 \times \frac{\text{height}}{\text{waist}}\) for men, \(76 - 20 \times \frac{\text{height}}{\text{waist}}\) for women) to provide a superior adiposity indicator over standard BMI.
How to Use
Key Features
Common Use Cases
Tips & Best Practices
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Body Adiposity Index (BAI) Calculator
Calculate Body Adiposity Index (BAI) online. Estimate your body fat percentage from hip circumference and height without using weight scales.
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Frequently Asked Questions
Q What is the Cedars-Sinai Relative Fat Mass formula?
For Men: RFM = 64 - (20 × Height / Waist). For Women: RFM = 76 - (20 × Height / Waist) [Height and Waist must be in identical units].
Q Where should the waist circumference be measured for RFM?
Measure at the horizontal level of the iliac crest (just above the hip bone, near the navel) at the end of a normal exhalation.
Q Why does the female RFM equation use a base constant of 76 versus 64 for males?
Biological women naturally possess higher baseline essential adipose tissue (for reproductive and endocrine function), which the formula models with the higher starting constant 76.