What is body surface area used for?

BSA is commonly used in medicine to calculate drug dosages (especially chemotherapy), assess cardiac function, and in some clinical research contexts, since some measurements scale better with surface area than with weight alone.

Which BSA formula is more accurate?

Both Du Bois and Mosteller are widely used and generally produce similar results; Mosteller is simpler to calculate by hand, while Du Bois is one of the oldest and most cited formulas.

Is a higher or lower BSA better?

BSA isn't a health metric to optimize — it simply reflects body size and is primarily useful as an input to other clinical calculations, not as a target itself.

Health & Fitness

Body Surface Area Calculator

Enter height and weight to calculate body surface area (BSA) in square meters, using two widely referenced formulas.

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Enter your height and weight above to calculate body surface area.

This result is an estimate for informational and educational purposes. It isn’t a diagnosis and isn’t a substitute for advice from a doctor, registered dietitian, or other qualified professional. See our methodology and sources for the formula used and its limitations.

How it works

BSA is calculated from height and weight using two different published formulas — Du Bois & Du Bois and Mosteller — which are both commonly referenced for estimating body surface area from simple measurements.

Formula & methodology

Two accepted formulas are calculated, and their average is also shown. Mosteller is simpler and popular in clinical dosing. Du Bois is one of the most cited. Both give results in square metres.

Du BoisBSA = 0.007184 × weight^0.425 × height^0.725

MostellerBSA = √( weight × height ÷ 3600 )

AverageAverage BSA = (Du Bois + Mosteller) ÷ 2

What each term means

Weight: Body weight in kilograms.
Height: Height in centimetres.
BSA: Body surface area, in m².

Worked example

For a weight of 70 kg and height of 175 cm, the Du Bois formula gives a BSA of about 1.85 m², close to Mosteller's estimate.

Common uses

—Reference calculations for clinical or pharmacological contexts where dosing scales with body surface area.
—Comparing the Du Bois and Mosteller formulas for a research or educational context.
—Providing a quick BSA estimate ahead of a clinician confirming the figure for medical use.

Important notes

—BSA is most often used in clinical and pharmacological contexts (such as certain medication dosing calculations) — always follow a clinician's guidance for medical decisions.
—The two formulas typically agree closely; larger differences can appear at extreme heights or weights.