Navy body fat calculator
Estimate body fat percentage with the Navy circumference-density method.
What this calculator covers
Use this Navy body fat calculator to estimate body fat percentage from circumference measurements and the published density equation.
The page shows the measurement term, the converted pace-free math, and the final percentage so the result can be checked before you move on.
Frequently asked questions
- Where exactly should I measure my waist circumference for this method?
- The Navy method measures waist at the narrowest point for men and at the navel level for women. Measuring at the wrong location introduces error, so consistent technique matters as much as reading the tape accurately.
- Why does the female formula include a hip measurement?
- Research behind the Navy density equations found that adding hip circumference improved the accuracy of the body-fat estimate for women. Men's formula uses only waist and neck because the hip term did not improve accuracy in the male sample.
- How does this method compare with skinfold calipers or DEXA?
- The Navy tape method is a field estimate that trades measurement convenience for some precision. Hydrostatic weighing and DEXA scanning measure tissue compartments more directly and are generally considered more accurate, but they require equipment and a trained technician.
- Can I use centimeters instead of inches?
- Yes — the unit system selector switches all measurement inputs between imperial (inches) and metric (centimeters). The underlying formula internally converts everything to metric-equivalent lengths before computing the result.
Tool
Run the calculation
Result
RESULT · BODY FAT
â„–221
Primary result
28.3%
Using the Navy density formula, the selected female measurements estimate body fat at 28.3%.
- Height used
- 65.0 in
- Circumference term
- 139.7 cm
- Method
- U.S. Navy (female)
- Estimated body fat
- 28.3%
Step-by-step solution
- 1.Convert the tape measurements to inches to build the circumference term: 30 + 38 - 13 = 55 in.
- 2.Translate the height and circumference term into metric-equivalent lengths for the Navy density constants: 165.1 cm height and 139.7 cm for the body-composition term.
- 3.Apply the female Navy density equation and convert it into body-fat percentage for 28.3%.
Walkthrough
Visual walkthrough
The Navy method turns body measurements into a density estimate first, then converts that density into body-fat percentage.
01
Build the circumference term
30 + 38 - 13 = 55 in
Men use waist minus neck, while women use waist plus hips minus neck.
02
Convert to metric-equivalent lengths
139.7 cm · 165.1 cm
This version of the density equation uses metric-equivalent lengths inside the logarithms.
03
Read the density-based percentage
The result is convenient for field checks, but measurement error still matters and lab methods remain more precise.
28.3%