Body Fat Calculator
Estimate body fat percentage
Body Fat Measurements (US Navy Method)
Measure at belly button level, relaxed
Body Fat Analysis
About Body Fat Calculator
The US Navy body fat method is one of the most accurate at-home body fat measurement techniques. Developed by the Naval Health Research Center, it uses simple circumference measurements to estimate body fat percentage with 95-98% accuracy compared to hydrostatic weighing.
Unlike BMI which can't distinguish muscle from fat, body fat percentage directly measures your body composition. This is crucial for athletes, fitness enthusiasts, and anyone serious about health tracking.
Body Fat Classification Chart
| Category | Men | Women |
|---|---|---|
| Essential Fat (Men/Women) | 2-5% | 10-13% |
| Athletes | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Average/Acceptable | 18-24% | 25-31% |
| Obese/High Risk | 25%+ | 32%+ |
US Navy Body Fat Formula
For Men
% Body Fat = 86.010 × log₁₀(Waist - Neck) - 70.041 × log₁₀(Height) + 36.76
Measurements in inches. The calculator converts your centimetres (÷ 2.54) first.
For Women
% Body Fat = 163.205 × log₁₀(Waist + Hip - Neck) - 97.684 × log₁₀(Height) - 78.387
Measurements in inches. The calculator converts your centimetres (÷ 2.54) first.
How to Take Accurate Measurements
- • Neck: Measure just below the Adam's apple (men) or voice box (women), tape sloping slightly downward at front
- • Waist: Measure at belly button level (navel), tape snug but not compressing skin, after exhaling normally
- • Hip (women only): Measure at widest point of hips/buttocks, tape parallel to floor
- • Use a flexible but non-stretchable measuring tape (cloth or plastic)
- • Take measurements without clothing or over very thin clothing
- • Stand straight, feet together, and relax muscles during measurement
- • Take each measurement twice and average for consistency
Frequently Asked Questions
Built and maintained by Sanjay Singh · Founder, Numrexo
Builds and maintains the calculators on Numrexo. Each tool's formula is documented on its page, and any reference source it relies on is listed under Method and references.
Last updated: · Calculations run in your browser. Nothing you enter is sent to us or stored.
Method and references
- Method: US Navy circumference formula (Hodgdon & Beckett)
- Body fat categories: American Council on Exercise ranges
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