US Navy Body Fat Calculator
Estimate body-fat percentage from simple tape measurements using the US Navy circumference equations.
US Navy Body Fat Calculator
Medical Disclaimer: This is for informational purposes only—not medical advice. Consult a healthcare professional.
How this is calculated
Formula: US Navy circumference equations
The method relates height to neck and abdominal circumference for men, and to neck, waist, and hip circumference for women.
Logarithmic equations convert those measurements into an estimated body-fat percentage. Consistent tape placement and tension strongly affect the result.
The Navy method is convenient but less precise than a well-conducted clinical assessment such as DXA. Track trends under similar conditions rather than treating one result as exact.
Measurement locations
| Measurement | Where to measure | Technique |
|---|---|---|
| Neck | Just below the larynx | Tape slopes slightly downward in front |
| Waist/abdomen | Preset-specific site near navel or narrowest waist | Relaxed after a normal exhale |
| Hips | Widest buttock circumference | Tape horizontal and snug |
| Height | Standing without shoes | Look straight ahead |
Improve measurement consistency
Tips
- •Use a flexible, non-stretch tape against skin or thin clothing.
- •Measure twice and repeat if readings differ noticeably.
- •Do not pull the tape tightly enough to compress tissue.
- •Measure at the same time of day when tracking change.
- •Follow the calculator labels because official sites differ by sex.
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Frequently asked questions
It is useful for accessible screening and trends, but individual error of several percentage points is possible due to anatomy and measurement technique.
This is an approximate screening calculation, not a medical diagnosis or an official military determination. Measurement error and individual anatomy affect results. Consult a clinician for health decisions.
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