Body Fat Calculator
Estimate body fat percentage using the U.S. Navy circumference method. Choose your sex and enter body measurements in centimeters.
How to Use the Body Fat Calculator
Enter the requested measurements to estimate body-fat percentage using the calculator's formula.
Practical Example
Two people with the same body weight can receive different estimates when waist, neck, height or sex inputs differ.
Factors That Affect the Result
Measurement technique, hydration, body shape and the selected estimation formula can all affect the result.
Frequently Asked Questions
Is this a medical measurement?
No. It is an estimate.
Can measurement error change the result?
Yes. Small tape-measure differences can matter.
Is body fat the same as BMI?
No. BMI is based on weight and height.
Related Tools
Interpreting Body Fat Estimates
Body-fat calculators estimate the proportion of body weight that is fat mass using the measurements and formula supported by the tool. Different methods can produce different results because circumference formulas, bioelectrical-impedance devices, skinfold measurements and laboratory techniques each rely on different assumptions. Small changes in measurement technique can also affect an estimate, especially when waist, neck or hip circumference is involved. For progress tracking, consistency is often more useful than comparing numbers from several unrelated methods. Measure under similar conditions and focus on trends rather than a single reading. Body-fat percentage is only one part of health and fitness assessment and should not be treated as a diagnosis. Athletes, older adults, pregnant people and individuals with medical conditions may require more specialized interpretation from a qualified professional.