Body Surface Area Calculator
Calculate body surface area (BSA) in square meters using the Mosteller formula, commonly used for medication dosing.
- Your BSA1.88 m²
- Standard Reference (1.73 m²)1.73 m²
Drug doses are often standardized to a 1.73 m² "reference" adult — yours is larger by 0.15 m².
ƒShow your work
BSA = √(height(cm) × weight(kg) / 3600)
About the Body Surface Area Calculator
Body surface area (BSA) estimates the total area of your skin in square meters, calculated here with the Mosteller formula from your height and weight. It's a clinical measurement, most commonly used to scale medication doses — particularly chemotherapy — more precisely than a flat dose or a weight-only dose would.
This calculator reproduces the formula for informational purposes, but BSA-based dosing in real clinical settings is determined and verified by a physician or pharmacist, never by a self-service calculator — do not use this output to adjust or self-manage any actual medication dose.
It's used by clinicians and students who want a quick BSA reference calculation, or by anyone curious how their own BSA compares to the standard 1.73 m² reference adult that many dosing formulas and lab-value normalizations are built around.
Height and weight are calculated locally in your browser here, with nothing saved or sent off your device.
How it’s calculated
The Mosteller formula is BSA = √(height(cm) × weight(kg) / 3600) — a simpler square-root formula that's widely used in practice because it's easy to compute correctly while remaining close to more complex historical formulas like Du Bois across most adult body sizes.
The 1.73 m² reference figure shown for comparison represents a standardized 'average' adult body surface area, a benchmark against which many drug doses and some lab values (like eGFR) are traditionally normalized.
Frequently asked questions
What is body surface area used for?
It's most commonly used in medicine to calculate drug doses — especially chemotherapy and some other high-precision medications — more accurately than dosing by weight alone, since BSA correlates better with certain physiological processes like blood volume and metabolic rate.
Is this calculator safe to use for determining my medication dose?
No — actual medication dosing must be calculated and verified by a physician or pharmacist using clinical protocols. This calculator is for general informational and educational reference only.
What is the Mosteller formula and why is it used?
It's a simplified square-root formula for estimating BSA from height and weight, popular because it's easy to compute by hand or calculator while staying close to the results of older, more complex formulas like Du Bois for most adult sizes.
Why is 1.73 m² used as a reference?
It represents a standardized 'typical adult' body surface area that many medical formulas and lab value normalizations (like eGFR results) are built around, letting results be compared on a consistent scale regardless of an individual's actual size.
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