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endocrinology

Relative Fat Mass (RFM) Calculator

Simple anthropometric formula estimating body fat percentage using height and waist circumference. More accurate than BMI for predicting body fat. Males: RFM = 64 − (20 × height/waist). Females: RFM = 76 − (20 × height/waist).

Score interpretation

Below Normal Fat (Men) 0–19.9

RFM <20% (men) — below average body fat percentage

→ No fat loss intervention needed; reassess if BMI or risk factors indicate concerns; monitor for sarcopenic obesity if muscular

Normal Range (Men) / Overweight (Women) 20–29.9

RFM 20–30% (men) or 30–40% (women) — normal to borderline fat range

→ Lifestyle advice for maintaining healthy body composition; regular physical activity; dietary counselling if trending upward; annual reassessment

Obesity Threshold Likely 30–100

RFM ≥30% (men) / ≥40% (women) — obesity-level body fat

→ Assess metabolic risk (blood pressure, glucose, lipids); calculate EOSS stage; lifestyle intervention; consider referral to weight management service; pharmacotherapy or bariatric surgery evaluation if BMI ≥35 with comorbidities

Interpretation bands for the Relative Fat Mass. Apply clinical judgement and local guidance.

References

Related

Curated clinical cross-links plus same-class fallbacks.

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.