Health & FitnessFormula-based · Runs in your browser

BMI Calculator

Calculate BMI, BMI Prime, ponderal index, adult category, and the corresponding healthy-weight range in metric or imperial units.

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Inputs

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Required
years
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kg
Required
cm

Result

Updates as valid inputs change.

Calculated locally
BMI is a screening measure, not a diagnosis. People under age 20 require age- and sex-specific growth-chart percentiles.
BMI
Screening category
BMI 18.5–24.9 weight range
BMI Prime
Ponderal index

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Calculation steps

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  1. 1

    Formula selected

    The calculator uses the following formula or method.

    BMI = weight (kg) ÷ height² (m²); BMI Prime = BMI ÷ 25; ponderal index = weight ÷ height³.

  2. 2

    Values entered

    Your values are placed into the calculation.

    Enter values to see what is used in this step.

  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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Data and privacy

How it works

The calculator reports BMI, the adult screening category, BMI Prime, ponderal index, and the weight interval corresponding to BMI 18.5 through 24.9 at the entered height.

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

8
  • ?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: 70 · Used when unitSystem = metric

  • ?heightCm= Height

    Number · Required · Default: 175 · Used when unitSystem = metric

  • ?weightLb= Weight

    Number · Required · Default: 154 · Used when unitSystem = imperial

  • ?feet= Height feet

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

  • ?inches= Height inches

    Number · Required · Default: 9 · Used when unitSystem = imperial

Outputs

5
  • bmi BMI

    Number · Primary output

  • category Screening category

    Text

  • healthyRange BMI 18.5–24.9 weight range

    Text

  • bmiPrime BMI Prime

    Number

  • ponderalIndex Ponderal index

    Number · Suffix: kg/m³

Limits

BMI does not distinguish fat from muscle or describe fat distribution. Children and teenagers require age- and sex-specific percentile interpretation rather than adult cutoffs.

Sources
Limitations
  • BMI is a screening measure, not a diagnosis. People under age 20 require age- and sex-specific growth-chart percentiles.
  • Health results are educational estimates, not a diagnosis or treatment recommendation. Individual circumstances may require a qualified clinician's assessment.