Athlete Body Fat Percentage Calculator
Estimate your body fat percentage using the U.S. Navy circumference method — widely used for athletes and fitness assessments.
Formula — U.S. Navy Circumference Method
Male:
BF% = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76
Female:
BF% = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387
All measurements in inches. Developed by Hodgdon & Beckett (1984) for the U.S. Navy.
Fat Mass = BF% × Total Weight
Lean Mass = Total Weight − Fat Mass
Assumptions & References
- Based on the U.S. Navy circumference method (Hodgdon & Beckett, 1984), validated for athletic populations.
- Waist is measured at the navel level; hip at the widest point (females only); neck just below the larynx.
- Accuracy is ±3–4% compared to DEXA or hydrostatic weighing under ideal measurement conditions.
- Athlete body fat categories: Males 6–13%, Females 14–20% (American Council on Exercise).
- Results may be less accurate for individuals with atypical fat distribution patterns.
- Not a substitute for clinical body composition assessment (DEXA, BodPod, hydrostatic weighing).
- Reference: Hodgdon, J.A. & Beckett, M.B. (1984). Prediction of percent body fat for U.S. Navy men and women. Naval Health Research Center.