Body Fat Percentage Calculator
Estimate your body fat percentage using the US Navy circumference method.
How to use this tool
Select your sex, enter your height, and measure your neck and waist circumference (and hips, for women) in centimeters with a flexible tape measure. See the About section for exactly where to measure.
About this calculation
Uses the US Navy circumference method. Neck: just below the larynx. Waist: at the navel, standing relaxed. Hip (women only): at the widest point. For men: %BF = 495 / (1.0324 − 0.19077×log₁₀(waist−neck) + 0.15456×log₁₀(height)) − 450. For women: %BF = 495 / (1.29579 − 0.35004×log₁₀(waist+hip−neck) + 0.22100×log₁₀(height)) − 450.
Source: Hodgdon & Beckett, US Navy circumference method (Naval Health Research Center, 1984). This tool is for general informational purposes only and is not medical advice.
Frequently asked questions
How accurate is the US Navy method?
It's a reasonable estimate for most people, with an error margin of roughly ±3-4 percentage points compared to more precise methods like DEXA scans. Accuracy depends heavily on measuring circumferences correctly and consistently.
Where exactly do I measure?
Neck: just below the larynx, tape sloping slightly downward at the front. Waist: at the navel, standing relaxed (not sucked in). Hip (women only): at the widest point of the hips/buttocks. Measure in centimeters, without clothing bunching under the tape.
Is this medical advice?
No. This is a general estimate for informational purposes, not a medical or diagnostic measurement. For accurate body composition assessment, consult a healthcare professional or use a clinical method like DEXA.