Online Tools

    Body Surface Area Calculator

    Calculate body surface area with Mosteller, Du Bois, Haycock, Boyd, and Gehan equations using metric or US units, with medical-use cautions.

    BSA formulas use height and weight. Sex is not part of these equations.

    Body Surface Area Estimate

    Body surface area, or BSA, estimates external body surface from height and weight. English-language BSA calculator results commonly compare Mosteller, Du Bois, Haycock, Boyd, and Gehan equations.

    Mosteller body surface area equation.

    Medical context required
    BSA may be used in clinical protocols, but this calculator does not prescribe medication, chemotherapy, or treatment. Dose decisions require the drug label, protocol, labs, organ function, and clinician judgment.

    Why Several Equations Are Shown

    Different BSA equations can diverge, especially at very small or very large body sizes. Comparing equations helps reveal sensitivity instead of presenting one value as exact.

    • Mosteller is a common simple default.
    • Du Bois is the historical reference equation.
    • Haycock is often cited for pediatric and adult comparison.
    • Boyd and Gehan provide additional comparison points.

    Frequently Asked Questions

    Sources and References

    Calculations are based on the listed reference sources. Links open in a new tab.

    Updated:

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