Body Fat Calculator (US Navy Method)
Estimate body fat percentage from tape measurements using the US Navy circumference formula.
- Body fat percentage16.9
Inputs used
- SexMale
- Height175 cm
- Neck circumference38 cm
- Waist circumference85 cm
- Hip circumference (women only)95 cm
About this calculator
The US Navy method estimates body fat from circumference measurements — no calipers or scans needed. Men measure neck and waist; women also measure hips (the hip field is ignored for men). Measure the waist at the navel, the neck below the larynx, and the hips at the widest point, with the tape level and snug but not compressing.
Rough reference ranges for adults: essential fat sits below about 5% (men) / 13% (women); athletes typically 6–13% / 14–20%; fitness 14–17% / 21–24%; average 18–24% / 25–31%. Tape-based estimates are usually within 3–4 percentage points of lab methods — good for tracking change over time, less exact as a one-off number.
The waist must measure larger than the neck for the formula to work. Results are informational, not a medical assessment.
Frequently asked questions
How accurate is the US Navy body fat method?
It uses only tape measurements and the difference between waist and neck (plus hips for women), and is usually within about 3–4 percentage points of lab methods like DEXA. That makes it good for tracking change over time, less exact as a single one-off number.
Why do women measure their hips but men don't?
The formula uses different equations by sex: for women, adding the hip circumference improves the estimate because women tend to store more fat around the hips. For men the neck and waist alone give the best fit, so the hip field is ignored.
What is a healthy body fat percentage?
Rough adult reference ranges are roughly 14–17% (men) / 21–24% (women) for the fitness category and 18–24% / 25–31% for average, with athletes lower and essential fat below about 5% / 13%. Healthy ranges shift with age and these are population guides, not medical cutoffs.
How should I take the measurements?
Measure the waist at the navel, the neck just below the larynx and, for women, the hips at their widest point, keeping the tape level and snug without compressing the skin. Consistent technique matters more than perfection, since the estimate depends on the waist reading exceeding the neck reading.
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Results are informational only — not financial, medical or legal advice.