Body fat percentage is a more informative health metric than BMI because it distinguishes fat mass from muscle mass. Here are four methods ranked by accuracy and convenience.
Method 1 — Navy Circumference Method (Best for Home Use)
The US Navy body fat formula uses measurements of neck, waist and hips (women only) to estimate body fat percentage. For men: %BF = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76. For women: %BF = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387.
Measurement tips: Measure waist at narrowest point (or navel for men). Measure neck just below larynx. Measure hips at widest point. Take measurements in centimetres or inches consistently. Our calculator handles both units.
Method 2 — Smart Scales (BIA)
Bioelectrical impedance analysis (BIA) scales send a small current through the body and estimate fat based on resistance. Convenient but variable — accuracy affected by hydration levels, time of day, and recent exercise. Results can vary 3–5% depending on conditions. Useful for tracking trends over time rather than absolute values.
Method 3 — Skinfold Calipers
Pinch-and-measure calipers at specific sites (3–7 sites depending on protocol) and use a formula to estimate total body fat. Accuracy is highly dependent on technique — trained practitioners get results within 3–4% of DEXA. Consumer self-measurement is less reliable but reasonably useful for tracking change.
Healthy Body Fat Ranges
Men: essential fat 2–5%, athletes 6–13%, fitness 14–17%, acceptable 18–24%, obese 25%+. Women: essential fat 10–13%, athletes 14–20%, fitness 21–24%, acceptable 25–31%, obese 32%+. Women carry higher essential fat due to hormonal and reproductive requirements.
Calculate your body fat % using the Navy circumference method.
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