Health / Browser calculator

Body Fat Calculator

Body Fat Calculator works from the inputs you provide and returns circumference body-fat estimate (%). Use the calculation panel to explore a scenario, then check the formula and limitations before applying the result.

Your inputs

Minimum: 1e-06 · Maximum: 300
Minimum: 1e-06
Minimum: 1e-06
Minimum: 1e-06

Your results

Enter your values and calculate to see the result.

This calculator is for informational purposes only and is not a substitute for professional medical advice.

Formula and calculation method

US Navy circumference estimate: male = 86.010 log₁₀(waist−neck) − 70.041 log₁₀(height) + 36.76; female = 163.205 log₁₀(waist+hip−neck) − 97.684 log₁₀(height) − 78.387. All lengths are inches.

Uses the legacy US Navy circumference equation. The Army-labeled tool is not an official current Army assessment and does not determine military compliance. Tape measurement technique strongly affects results.

How to use body fat calculator

  1. Set Measurement system by choosing the option that matches your calculation.
  2. Set Height (cm or inches). The example below uses 175.
  3. Set Waist circumference (cm or inches). The example below uses 85.
  4. Set Neck circumference (cm or inches). The example below uses 38.
  5. Set Hip circumference, female equation (cm or inches). The example below uses 95.
  6. Set Sex parameter used by equation by choosing the option that matches your calculation.
  7. Select Calculate to update the result. Reset restores the illustrated inputs. Copy, print or download your own result if you need a record.

Worked example

Example inputs
Measurement system
Metric (kg, cm)
Height (cm or inches)
175
Waist circumference (cm or inches)
85
Neck circumference (cm or inches)
38
Hip circumference, female equation (cm or inches)
95
Sex parameter used by equation
Male
Circumference body-fat estimate (%)
17.00771917

Factors affecting your result

Uses the legacy US Navy circumference equation. The Army-labeled tool is not an official current Army assessment and does not determine military compliance. Tape measurement technique strongly affects results.

Changing measurement system changes the scenario being evaluated. Adjust one input at a time when comparing results, keep a copy of the assumptions, and compare values using the same unit and period. A precise arithmetic result does not make an uncertain assumption precise.

Frequently asked questions

How does the body fat calculator work?

US Navy circumference estimate: male = 86.010 log₁₀(waist−neck) − 70.041 log₁₀(height) + 36.76; female = 163.205 log₁₀(waist+hip−neck) − 97.684 log₁₀(height) − 78.387. All lengths are inches.

What inputs does Body Fat Calculator need?

Enter measurement system, height (cm or inches), waist circumference (cm or inches), neck circumference (cm or inches), hip circumference, female equation (cm or inches), sex parameter used by equation. Choose values that correspond to the same situation and measurement convention.

How should I interpret the body fat calculator result?

Uses the legacy US Navy circumference equation. The Army-labeled tool is not an official current Army assessment and does not determine military compliance. Tape measurement technique strongly affects results.

Are my body fat calculator inputs uploaded?

No. The calculation runs in this browser. Favorites, recent tool names, theme and formatting preferences may be saved locally, but calculation inputs are not sent to a calculation server or stored by this website. Shared links do not include entered values.

Method reference

Maintained by Calculators.buzz Editorial Team. Implementation date: . No professional credentials or clinical review are claimed. Read our methodology policy.