Body Fat Calculator
Estimate your body fat percentage using the US Navy circumference method. Compare to healthy ranges and get actionable guidance. Free, instant, no equipment needed.
All calculations run instantly in your browser. No data is sent to any server.
Disclaimer: Results are for informational purposes only and do not constitute medical advice, diagnosis, or treatment. Consult a qualified healthcare professional for personal guidance.
US Navy Body Fat Method
The US Navy circumference method estimates body fat from waist, neck, and hip (women only) measurements relative to height. It is validated against hydrostatic weighing and DEXA scanning, with a typical error of ±3–4%. It is significantly more informative than BMI because it estimates actual fat mass rather than using weight as a proxy.
Body Fat vs. BMI
BMI cannot distinguish muscle from fat. Two people with identical BMIs can have vastly different body compositions. Body fat percentage is a more direct health indicator: high body fat (particularly visceral fat around the abdomen) is directly linked to insulin resistance, cardiovascular risk, and inflammation, independent of BMI.
FAQs
Healthy body fat ranges?
Men: 8–19% healthy, 6–13% athlete. Women: 21–33% healthy, 14–20% athlete. Below essential fat levels is dangerous.
How accurate is this formula?
±3–4% vs. DEXA (gold standard). Underestimates in very muscular individuals; overestimates with high visceral fat.