Health & Fitness

Navy Body Fat Calculator

Using the U.S. Navy circumference method, this tool estimates body fat percent from sex, height, neck, and waist (plus hip for women). A man 175 cm tall with a 38 cm neck and 85 cm waist gets about 16.9 percent.

What this calculator does

The Navy Body Fat Calculator estimates your result instantly from the values you enter, using standard health & fitness formulas. Using the U.S. Navy circumference method, this tool estimates body fat percent from sex, height, neck, and waist (plus hip for women). A man 175 cm tall with a 38 cm neck and 85 cm waist gets about 16.9 percent. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.

Result

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Body Fat %

About Navy Body Fat Calculator

The Navy Body Fat Calculator applies the U.S. Navy circumference method. It uses base-10 logarithms of your measurements: for men, waist minus neck and height; for women, waist plus hip minus neck and height. Enter measurements in centimetres to get an estimated body fat percentage.

Formula & Mathematical Calculation

Body Fat % = f(Sex, Height (cm), Neck (cm), Waist (cm), Hip (cm, women))

Calculated according to standard health formulas implemented in the calculator core.

Calculation Example

Select Male, enter Height 175 cm, Neck 38 cm, and Waist 85 cm. The tool applies the Navy male formula and shows a Body Fat % of about 16.9 %.

Key Benefits

  • Implements the established U.S. Navy circumference formula
  • Uses sex-specific equations, adding hip for women
  • Needs only a tape measure and height, no calipers
  • Returns body fat as a single percentage

How to Use this Calculator

  1. Select sex and enter height
    Choose Male or Female and enter Height (cm).
  2. Enter circumferences
    Enter Neck and Waist in cm, and Hip in cm if Female is selected.
  3. Calculate
    Click Calculate and read the Body Fat % box.

Assumptions & Limitations

What the calculation assumes

  • Every value you enter is treated as an exact, known amount.
  • Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
  • Results use standard published formulas and account only for the values entered above.
  • Rounding is applied for display; the underlying calculation uses your full precision.
  • Results are returned in the same units you enter, unless the tool states the output unit.

What it does not cover

  • Navy Body Fat Calculator produces a calculated result for reference and learning, not a certified or official measurement.
  • Real-world outcomes differ when tolerances, rounding rules or local standards apply.
  • Definitions and standards vary by region and change over time; verify the convention that applies to your case.
  • Figures are only as accurate as the inputs you supply — check them before acting on the result.
  • For work where the result carries real consequences, confirm it against an authoritative source.

Frequently Asked Questions

Men: height, neck, and waist. Women: height, neck, waist, and hip. Sex selects the matching equation.

The formula takes the logarithm of waist minus neck (or waist plus hip minus neck for women), so that difference must be positive or the tool shows an error.

The U.S. Navy circumference method, using base-10 logarithms of the measurements as noted in the result.

Yes. If the formula produces a negative value, the tool floors it at 0 percent.

Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.