Estimate body fat percentage from neck, waist, and hip measurements using the U.S. Navy circumference method. Enter your details below — the calculation runs entirely in your browser.
Frequently asked questions
How accurate is the Navy method?
Circumference-based estimates typically land within about 3–4 percentage points of hydrostatic weighing for most people, but accuracy depends heavily on measurement consistency. Measure at the same sites, at the same time of day, and have someone help when possible.
Why do women measure hips too?
The Navy equation for women includes hip circumference because fat distribution differs by sex; the male equation uses only neck and waist.
What is a healthy body fat percentage?
ACE reference ranges: for men, 6–24% spans athlete to average, with 25%+ listed as obesity range; for women, 14–31% spans athlete to average, with 32%+ as obesity range. Needs differ by age and goals — a professional can interpret yours in context.
This calculator provides estimates for informational and educational purposes only. It is not medical advice and does not diagnose or treat any condition. Consult a qualified healthcare professional before starting any diet, exercise, or weight-management program.