Free calculator
Body Fat Calculator (US Navy)
You only need a soft tape. Measure the neck below the larynx, the waist at the navel (men) or narrowest point (women) and, for women, the hips at the widest point.
How it works
Men: 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76. Women: 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387, all in inches. Categories follow the American Council on Exercise.
The method can be off by 3–4 percentage points. Use it for trends, measuring the same way each time.
Frequently asked questions
What is a healthy body fat percentage?
Roughly 14–24% for women and 6–17% for men for fit-to-average adults; Indians tend to have more body fat at the same BMI.
Is this as accurate as a DEXA scan?
No. DEXA and clinical methods are more precise; tape measures are convenient and free.
How often should I measure?
Every 2–4 weeks, same time of day, same tape position.
General estimates for information only. Not medical or professional advice. Nothing you enter is saved or sent to us.
