Body Fat Calculator

Body fat percentage measures the proportion of your total weight that is fat tissue versus lean mass (muscle, bone, organs, water). The US Navy method — one of the most practical formulas — uses neck, waist, and hip circumference measurements along with height. For men, the formula focuses on the difference between waist and neck measurements; for women, it adds hip circumference. Essential fat — the minimum needed for normal physiological function — is approximately 3-5% for men and 10-13% for women. Athletic individuals typically range from 6-13% (men) or 14-20% (women). Fit ranges are 14-17% (men) and 21-24% (women). Average ranges are 18-24% (men) and 25-31% (women). Above 25% for men or 32% for women is classified as obese by most health organizations. Unlike BMI, body fat percentage distinguishes between muscle and fat — a muscular person at 90kg might have 12% body fat while someone at the same weight with less muscle might be at 28%. All measurements are processed locally in your browser.

The most accessible methods vary in accuracy. Tape measurements (used by this tool and the US military) are accurate to within 3-4% when done consistently. Bioelectrical impedance scales (common bathroom smart scales) can vary by 5% or more depending on hydration — drinking 500ml of water right before measuring can shift readings by 2-3 percentage points. Skinfold calipers, when used by a trained professional, achieve 3% accuracy. DEXA scans (dual-energy X-ray absorptiometry) are considered the gold standard at ±1% accuracy but cost $50-150 per scan. Hydrostatic weighing (underwater) is similarly accurate but less available. For tracking progress, consistency matters more than absolute accuracy. Measure at the same time of day, under the same conditions. A tape-measure reading that drops from 22% to 19% over three months reliably indicates fat loss, even if the true values differ by a few percentage points. This calculator uses the US Navy formula with your measurements to provide a reliable estimate.