Health & FitnessFormula-based · Runs in your browser

Body Fat Calculator

Estimate body-fat percentage with the U.S. Navy circumference method and compare it with a BMI-based estimate.

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Inputs

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years
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kg
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cm
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cm
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cm
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cm

Result

Updates as valid inputs change.

Calculated locally
Circumference methods estimate body composition and are not diagnostic measurements.
Navy body-fat estimate
Body-fat category
BMI-based estimate
Estimated fat mass
Estimated lean mass
BMI

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Calculation steps

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  1. 1

    Formula selected

    The calculator uses the following formula or method.

    U.S. Navy circumference equations use log10 of height and sex-specific circumference combinations; BMI estimate = 1.2×BMI + 0.23×age − 10.8×male − 5.4.

  2. 2

    Values entered

    Your values are placed into the calculation.

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  3. 3

    Result calculated

    The formula or method produces the following result values.

    Results will appear after a successful calculation.

  4. 4

    Answer formatted

    Displayed values are rounded and formatted using each output’s configured precision.

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How it works

The method combines height with neck and waist measurements for men, and height with neck, waist, and hip measurements for women. The calculator also displays a separate BMI-based estimate for context.

Input query strings and outputs

Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.

Input query strings

14
  • ?unitSystem= Units

    Choice · Required · Default: metric · Accepted values: metric, imperial

  • ?sex= Sex used by equation

    Choice · Required · Default: male · Accepted values: male, female

  • ?age= Age

    Number · Required · Default: 30

  • ?weightKg= Weight

    Number · Required · Default: 80 · Used when unitSystem = metric

  • ?heightCm= Height

    Number · Required · Default: 180 · Used when unitSystem = metric

  • ?neckCm= Neck circumference

    Number · Required · Default: 39 · Used when unitSystem = metric

  • ?waistCm= Waist circumference

    Number · Required · Default: 90 · Used when unitSystem = metric

  • ?hipCm= Hip circumference (used for female equation)

    Number · Required · Default: 100 · Used when unitSystem = metric

  • ?weightLb= Weight

    Number · Required · Default: 176 · Used when unitSystem = imperial

  • ?feet= Height feet

    Number · Required · Default: 5 · Used when unitSystem = imperial

  • ?inches= Height inches

    Number · Required · Default: 11 · Used when unitSystem = imperial

  • ?neckIn= Neck circumference

    Number · Required · Default: 15.4 · Used when unitSystem = imperial

  • ?waistIn= Waist circumference

    Number · Required · Default: 35.4 · Used when unitSystem = imperial

  • ?hipIn= Hip circumference (used for female equation)

    Number · Required · Default: 39.4 · Used when unitSystem = imperial

Outputs

6
  • bodyFat Navy body-fat estimate

    Percentage · Primary output

  • category Body-fat category

    Text

  • bmiEstimate BMI-based estimate

    Percentage

  • fatMass Estimated fat mass

    Text

  • leanMass Estimated lean mass

    Text

  • bmi BMI

    Number

Measurement limit

Hydration, tape placement, posture, and body shape can affect the estimate. Clinical methods may produce different results.

Sources
Limitations
  • Circumference methods estimate body composition and are not diagnostic measurements.
  • Health results are educational estimates, not a diagnosis or treatment recommendation. Individual circumstances may require a qualified clinician's assessment.