Using the Body Fat Calculator
Enter every measurement in centimeters, even though the equation converts them to inches internally. The female equation uses hip circumference as well as waist and neck; the male equation does not use the hip entry. Small differences in tape placement can noticeably change the answer.
Worked example
Use the example inputs below to reproduce this result. These are the form's starting values, not recommended targets. Changing your inputs updates your result above; this worked example stays fixed for comparison. Results are rounded for display.
Example inputs
- Sex used by the equation
- Male
- Height (cm)
- 175
- Waist / abdomen (cm)
- 85
- Neck (cm)
- 38
- Hips (cm; female equation only)
- 95
Example result
- Estimated body fat (%)
- 17.007719
Method and assumptions
US Navy circumference equation, converting centimeters to inches. An adult population estimate, not a body-composition measurement or an official service assessment.
Reference: calculator.net — method and further reading
Make repeated measurements comparable
A measurement-based estimate can change because the body changed or because the measurement technique changed. Keep the location, units and method consistent when comparing records. The result cannot identify which explanation applies. A ratio or predicted percentage describes only the measurements used by that equation, not a complete assessment of health or fitness.
Common question
Is this the same as a body-composition scan?
No. The calculator predicts a percentage from body dimensions. It does not measure tissue directly, and different assessment methods can produce different estimates for the same person. Avoid treating the decimal places as evidence of clinical precision.
Guide updated .