Estimate body fat percentage using the US Navy method with waist, neck, and hip measurements. More accurate than BMI for body composition.
Measure at navel level
Measure below larynx
Widest point - required for women
Enter values above to see results
Male: %BF = 86.01×log(waist−neck) − 70.041×log(height) + 36.76logBase-10 logarithmwaistWaist circumference in cmneckNeck circumference in cmhipHip circumference in cm (women)The US Navy circumference method estimates body fat using body measurements. It is more accessible than DEXA scans or hydrostatic weighing and more accurate than BMI for body composition assessment. Accuracy is typically within 3-4% of laboratory methods.
Body fat percentage is a more informative measure of body composition than weight or BMI alone. Two people can have the same weight and BMI but very different body compositions - one may be muscular and lean while the other carries excess fat. Understanding your body fat percentage provides actionable insight for fitness and health goals.
Enter your height, waist, neck, and (for women) hip circumferences. The calculator uses the US Navy circumference method to estimate body fat percentage, classify your fitness category, and estimate fat and lean mass distribution.
This method requires only a measuring tape, making it accessible and repeatable at home. It is significantly more informative than BMI for fitness-oriented individuals and provides a baseline for tracking body composition changes over time.
Measurement accuracy is critical. Measure waist at navel level (not the narrowest point), neck just below the larynx, and hips at the widest point. Inconsistent measurement locations are the primary source of error. Take 2-3 measurements and use the average.
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