Body Fat Percentage Calculator
Estimate body fat percentage using the US Navy tape-measure method.
Pick male or female, enter height and circumference measurements in inches. Get an estimated body fat percentage and category.
Uses the US Navy method (waist, neck, height for men; add hip for women). Measurements in inches.
The US Navy method
The US Navy uses a tape-measure method to estimate body fat for service members. It is based on neck and waist measurements (and hip, for women), plus height. The formulas were derived from comparison with hydrostatic weighing for thousands of Navy personnel.
How to measure
- Neck: measure just below the larynx (Adam's apple), with the tape sloping slightly downward toward the front
- Waist: measure at the navel for men; at the narrowest point for women
- Hip (women only): measure at the widest point around the buttocks
- Height: standing straight without shoes
Use a soft cloth tape measure. Stand relaxed (do not suck in or push out the stomach). Take each measurement twice and average.
Body fat categories (general)
Men: Essential 2-5%, Athletes 6-13%, Fitness 14-17%, Average 18-24%, Obese 25%+
Women: Essential 10-13%, Athletes 14-20%, Fitness 21-24%, Average 25-31%, Obese 32%+
Women carry more essential fat than men due to reproductive physiology. Categories vary by source; these are American Council on Exercise classifications.
Accuracy
The Navy method is typically accurate to within 3-4 percentage points compared to hydrostatic weighing or DEXA scans. Less accurate than lab methods but much more accessible. For tracking changes over time, consistency in measurement technique matters more than absolute precision: measure the same way at the same time of day to see trends.
Informational only. This calculator is not medical advice and does not diagnose, treat, or prevent any condition. Always consult a qualified healthcare provider for medical decisions.