Body Fat % Estimator
Navy method estimation from your measurements. No calipers needed — strong everyday accuracy for most body types.
Your measurements
What this means
What to consider
Medications that may affect your result
Corticosteroids (prednisone, dexamethasone) cause fat redistribution, particularly to the abdominal area. This increases waist circumference and raises body fat estimates — even if total weight has not changed significantly.
Your baseline may differ from the general population. Discuss with your healthcare provider.
About this tool
Formula
U.S. Navy Body Fat Method. Male: 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76. Female: 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387. All measurements in centimetres.
Thresholds
Male: Essential <6% / Athletic 6–13% / Fit 14–17% / Healthy 18–24% / Increased risk 25%+
Female: Essential <14% / Athletic 14–20% / Fit 21–24% / Healthy 25–31% / Increased risk 32%+
Limitations
Margin of error ±3–4% vs DEXA scan. Less accurate for very short stature, limb differences, or significant edema. Measurement technique (tape placement, breathing state) affects accuracy. The Navy method estimates total body fat — it does not distinguish visceral from subcutaneous fat.
Sources
Hodgdon & Beckett, U.S. Navy Body Composition Method (1984). ACSM Body Fat Classification Guidelines.
Educational tool only. Not for diagnostic purposes. Consult a healthcare provider for medical decisions.