Educational estimate for adults, not medical advice, a diagnosis, or a treatment target. Review the method and limitations and discuss individual health questions with a qualified clinician.
Your result
How this calculation 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. Formula measurements are in inches.
Use the historical US Navy circumference equations as an educational estimate. Enter measurements in centimeters; the equation is calculated in inches. This is not a test of current military eligibility.
How to use this calculator
- Enter or choose equation.
- Enter or choose height (cm).
- Enter or choose abdomen / waist circumference (cm).
- Enter or choose neck circumference (cm).
- Enter or choose hip circumference (cm; female equation only).
- Select Calculate and review the result and assumptions.
Worked example
For a man at 180 cm height, 90 cm abdomen circumference, and 40 cm neck circumference, the historical equation estimates about 18.46% body fat.
Assumptions and limitations
Adults only. Tape-measure technique and population differences affect accuracy. Not a diagnosis, a current military standard, or a substitute for a clinical assessment. Men measure abdomen at the navel; women measure natural waist and widest hip.
Formula references
Frequently asked questions
Is this the current military body-composition standard?
No. It implements historical circumference equations for education, not current service eligibility rules.
Why can a measurement be rejected?
The logarithms require a positive circumference difference, and physically implausible results are rejected rather than presented as reliable.