Enter your height and weight to calculate body surface area using the Mosteller formula.

How to Use the Body Surface Area Calculator

Switch units first if needed; height and weight are the only two fields this one takes, and the square-meter figure updates the instant either changes.

Body surface area shows up constantly in medicine — chemotherapy dosing, burn-treatment fluid calculations, and cardiac index all scale to it rather than to weight alone, since it tracks the body's actual surface for heat exchange and drug distribution more closely than weight does on its own.

BSA (m²) = √(Height(cm) × Weight(kg) ÷ 3600)

This is the Mosteller formula, published by Dr. R.D. Mosteller in the New England Journal of Medicine in 1987 — simple, square-root-based, and close enough to more complex alternatives (DuBois, Haycock) that it's become the default in most clinical settings where BSA needs calculating quickly. The DuBois formula, one of the oldest and still occasionally cited, tends to produce results within a percent or two of Mosteller's for typical adult body proportions.

For clinical dosing, use the figure your care team calculates directly — medication doses tied to BSA should always come from a clinician working from verified measurements, not a self-service web calculator.