Body Fat Calculator

About the Body Fat Calculator

Body fat percentage is a far more meaningful measure of health and fitness than weight or BMI alone. Two people of identical weight and height can have dramatically different body compositions — one lean and muscular, the other carrying excess fat. Our body fat calculator uses the US Navy method (waist, neck, and hip measurements) which is accurate to within 3-4% of DEXA scan results for most people.

How It Works

The US Navy method uses circumference measurements. For men: %BF = 495 / (1.0324 − 0.19077 × log(waist − neck) + 0.15456 × log(height)) − 450. For women: %BF = 495 / (1.29579 − 0.35004 × log(waist + hip − neck) + 0.22100 × log(height)) − 450. Measure waist at the narrowest point (men) or navel (women), neck below the larynx, and hips at the widest point for women. All measurements in centimetres.

Tips & Best Practices

• ✓Measure at the same time each morning before eating for consistent comparisons.
• ✓Essential fat (minimum for survival): 2-5% men, 10-13% women.
• ✓Athletic range: 6-13% men, 14-20% women. Fitness range: 14-17% men, 21-24% women.
• ✓DEXA scan is the gold standard for body composition — use circumference methods for tracking trends.
• ✓Hydration status affects skinfold measurements but not circumference-based methods.

Who Uses This Calculator

Personal trainers tracking client progress, athletes monitoring competition readiness, people following body recomposition programs, and military personnel using the official service measurements all rely on body fat percentage calculations.