US Navy body fat calculator
Estimate body fat percentage from tape measurements using the US Navy circumference method.
A clear answer. Here’s how.
Uses the US Navy circumference equations (Hodgdon and Beckett, 1984) with measurements in inches. 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. Fat and lean mass multiply the result by body weight. The ACE bands label the result. Tape-measure error and body shape mean the estimate is often several points off.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Sex used by the equation
- Male
- Measurement units
- Metric (cm, kg)
- Height (cm, or inches)
- 180
- Neck circumference (cm, or inches)
- 38
- Waist circumference (cm, or inches)
- 85
- Body weight (kg, or pounds)
- 80
Example result
- Estimated body fat
- 16.2%
- Category (ACE bands)
- Fitness
- Fat mass
- 12.9 kg
- Lean mass
- 67.1 kg
US Navy circumference method (Hodgdon and Beckett, 1984) using base-10 logarithms of measurements in inches. Measure the neck below the larynx, the waist at the navel (men) or narrowest point (women), and the hip at the widest point. Typical error is several percentage points, so use it to track trends, not to diagnose.