About the body fat calculator
The U.S. Navy method estimates body fat from circumference measurements and height. It only needs a flexible tape measure, which makes it convenient for tracking changes over time. Like all field methods, it’s an estimate and can differ from laboratory measurements.
How to use this calculator
- Choose sex.
- Measure height, neck, and waist (and hips for women).
- Enter measurements in inches or centimeters.
Worked examples
- Neck 15 in, waist 34 in
- 86.010 × log₁₀(19) − 70.041 × log₁₀(70) + 36.76
About 17.5% body fat.
Measurement guidance
How to measure
Neck: just below the larynx. Waist: at the navel for men, narrowest point for women. Hips: widest point. Keep the tape level and snug.
Frequently asked questions
How accurate is the Navy method?
It’s a reasonable field estimate but can be off by several percentage points.
Why are formulas different by sex?
Fat distribution differs, so separate equations were developed.
Is this medical advice?
No.