Body Fat % (US Navy)
Unit System
Sex
cm
cm
cm
Body Fat %
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Category
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Body Fat % Ranges
Men: Essential 2-5, Athletes 6-13, Fitness 14-17, Average 18-24, Obese 25+
Women: Essential 10-13, Athletes 14-20, Fitness 21-24, Average 25-31, Obese 32+
About This Calculator
This calculator estimates body fat percentage using the official US Navy circumference method. For men, the formula uses waist and neck measurements along with height; for women, hip circumference is added to the equation. All values are converted to inches internally and processed through logarithmic formulas developed by the US Department of Defense. It is a practical alternative when lab methods like DEXA or hydrostatic weighing are not available, and is commonly used for military fitness assessments and personal health tracking. Results are estimates and can vary with measurement technique, so consistent placement of the tape measure is important for reliable readings.
FAQ
What formula is used?
The official US Navy method: for men,
86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76; for women,
163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387.
All measurements calculated in inches.
How should I measure?
Measure neck at the narrowest, waist at the navel (relaxed), and hip at the widest (women). Stand upright, exhale normally, keep the tape level and snug -- not tight.
Can I enter centimeters?
Yes. We accept cm and convert to inches internally before applying the US Navy equations.
How accurate is this?
It's an estimate. More precise methods (DEXA, hydrostatic) exist, but they're less accessible.