How to use this calculator
The US Navy circumference equations use inches internally. For the male equation measure the abdomen at the navel; for the female equation use the natural waist and widest hips.
- Enter estimate method, equation, units and review the remaining options.
- Select Calculate or change a value to update the result. Read the result label and units before copying.
- Use Reset to restore the worked starting values.
Formula and method
Indirect adult estimates, not clinical measurements. Circumference technique and the BMI model can produce different answers; no ideal-fat or weight-loss prescription is supplied.
Worked example
For a male at 175 cm, 85 cm abdomen and 38 cm neck, the estimate is about 17%.
Questions about body fat estimate calculator
How can I make circumference inputs more consistent?
Use the same measurement units and a consistent tape placement without compressing the skin. Enter the neck, waist, height, and any required hip measurement as labeled. The disclosed circumference method is an indirect estimate, not a clinical body-composition measurement.
What assumptions should I check?
Indirect adult estimates, not clinical measurements. Circumference technique and the BMI model can produce different answers; no ideal-fat or weight-loss prescription is supplied.
Are my inputs saved?
Calculations run in your browser. We store only tool IDs for favorites and recent tools. Sharing inputs in links is disabled for this category.
Health tools provide general estimates, not diagnoses or personal medical advice. BMI offers a labeled CDC child/teen reference; adult screening bands must not be applied to children. Discuss health and exercise decisions with a qualified professional. Read the tool-specific sources below for background on the method.