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Body Surface Area Calculator (Mosteller Formula)

Estimate body surface area from height and weight using the Mosteller formula, the method commonly referenced for clinical drug dosing, in metric (cm/kg) or imperial (in/lbs) units.

Body surface area
1.84 m²

How it works

This uses the Mosteller formula (Mosteller, 1987), the body surface area (BSA) estimate most commonly cited in current clinical references: BSA (m²) = √((height in cm × weight in kg) ÷ 3600). It's simpler than earlier formulas like DuBois & DuBois while producing very similar results, which is part of why it's widely used today.

The formula's coefficients are calibrated for centimeters and kilograms, so imperial entries are converted to metric before the calculation runs and the result comes out identical either way.

BSA is used clinically for dosing certain medications (notably chemotherapy drugs) instead of weight alone, since it correlates more closely with metabolic rate and cardiac output than body weight does on its own.

FAQ

Why use body surface area instead of just weight for dosing?

Weight alone doesn't scale evenly with metabolic rate, blood volume, or organ function across very different body sizes — surface area tracks those physiological factors more closely, which is why BSA-based dosing became standard for medications with a narrow safety margin, like many chemotherapy drugs.

Is this a substitute for a clinician's dosing calculation?

No — this is a reference implementation of the published formula for general informational use, not a substitute for a healthcare provider's dosing decision, which accounts for the specific drug, patient history, and clinical guidelines this calculator has no knowledge of.

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