Body Fat Percentage Calculator
Estimate your body fat percentage using the published U.S. Navy tape-measure method, in inches or centimeters.
This is an estimate based on the U.S. Navy circumference method. It is not a substitute for professional body composition testing (such as a DEXA scan) or medical advice.
How to Estimate Your Body Fat Percentage
- Select your sex — the calculator uses a different formula for men and women.
- Choose your unit — inches or centimeters — using the toggle.
- Enter your height, neck, and waist measurements (and hip, for women).
- Your body fat percentage and category appear automatically, updating live as you adjust any field.
Frequently Asked Questions
How accurate is the US Navy method?
It's generally accurate to within about 3-4% of body fat compared to more precise methods like hydrostatic weighing, according to the original validation research. It's a solid estimate for tracking progress over time, but it's not as precise as lab-based body composition testing.
What units can I use?
You can enter your measurements in inches or centimeters using the unit toggle — the calculator converts everything to a consistent unit internally before applying the formula, so your result will be the same either way.
Where exactly should I measure my waist, neck, and hip?
Measure your neck just below the larynx (Adam's apple), your waist at the narrowest point (or at the navel for men), and — for women — your hips at the widest point, keeping the tape measure snug but not compressing the skin.
Why does the formula ask for hip measurement only for women?
The U.S. Navy method uses two separate, sex-specific formulas because men and women tend to store body fat differently — the women's formula factors in hip circumference to better account for this, while the men's formula does not.
Is this a substitute for a DEXA scan or professional body composition testing?
No — this is a tape-measure estimate based on a published formula. For a precise, clinical measurement of body fat and lean mass, a DEXA scan or other professional body composition test performed by a qualified provider is more accurate.