Body Fat Calculator
Estimate your body fat percentage using the US Navy method.
Body fat estimates are screening tools and do not replace medical or professional assessment.
Body fat calculator
Enter measurements for a U.S. Navy body fat percentage estimate.
Estimated body fat percentage
17.0%
estimatedFitness range · 14–17%
This may fall within a commonly used fitness reference range.
Estimated fat mass
13.6 kg
Based on your entered weight and estimated body fat percentage.
Estimated lean mass
66.4 kg
Lean mass includes muscle, bone, water, organs, and other tissues.
Uses standard body fat estimation formulas. Reviewed for accuracy. Estimate only. Does not replace medical, dietetic, or professional fitness advice.
Personalized interpretation
Your estimated body fat percentage is 17.0%, based on the measurements entered.
This result may fall within the fitness range for your selected profile.
Body fat percentage is only one marker and should be interpreted alongside strength, waist measurement, health history, energy, sleep, and fitness goals.
Measurement technique can significantly affect the estimate. If you have concerns about weight, body composition, or health, consider speaking with a qualified healthcare professional.
Body fat category ranges
These body fat ranges are general references, not medical diagnoses. Ranges differ by sex, age, source, body type, and training history.
Essential fat
Men: 2–5%
Women: 10–13%
General reference range for essential physiological fat.
Athletic range
Men: 6–13%
Women: 14–20%
Often seen in trained athletic populations, but not required for health.
Fitness range
Men: 14–17%
Women: 21–24%
Commonly used reference range in fitness contexts.
Average range
Men: 18–24%
Women: 25–31%
General reference range that may vary by age and source.
Higher body fat range
Men: 25%+
Women: 32%+
May indicate higher body fat by common reference ranges.
What body fat percentage means
Body fat vs BMI
BMI
BMI uses height and weight only. It is easy to calculate but less specific about body composition.
Body fat percentage
Body fat percentage estimates body composition, but requires measurements and can vary by method.
Measurement methods and accuracy
Tape measurement formulas
Accessible and inexpensive, but sensitive to tape placement and measurement consistency.
Skinfold calipers
Uses skinfold thickness at specific sites and depends heavily on tester skill.
Bioelectrical impedance scales
Convenient at home, but hydration and timing can change readings.
DEXA scans
More detailed body composition assessment, usually performed in clinical or specialty settings.
Hydrostatic weighing
Laboratory-style method that estimates density using underwater weighing.
Each method has trade-offs. At-home methods are estimates, and consistency often matters more than perfect precision when tracking trends.
Formula explanation
This calculator uses the U.S. Navy circumference method. Measurements are converted to inches for the formula.
Men: Body Fat % ≈ 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76Women: Body Fat % ≈ 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387Waist, neck, hip, and height are circumference or length measurements. The equation is sex-specific and should be treated as an estimate, not a clinical body composition test.
Example: male profile
Height 70 in, waist 34 in, neck 15 in gives an estimate of about 17.5%.
Example: female profile
Height 65 in, waist 30 in, hip 38 in, neck 13 in gives an estimate of about 28.6%.
Limitations and healthy context
Body fat estimates can vary for many reasons. This calculator is not a diagnosis and should not replace professional assessment.
Sudden unexplained weight or body changes should be discussed with a healthcare professional.