Body Surface Area
Calculator

Body surface area (BSA) estimates the total area of skin covering your body and is widely used in medicine to dose chemotherapy drugs and other medications more precisely than weight-based dosing alone. It's also used in burn assessment and certain cardiac and kidney function calculations.

BSA correlates better than weight alone with metabolic processes like blood volume, cardiac output, and kidney filtration rate, which influence how a drug is distributed and cleared. This makes BSA-based dosing more consistent across patients of different shapes and sizes at the same weight.

Common formulas include the Mosteller formula (a simple square-root formula) and the more complex DuBois and DuBois formula, both of which use height and weight. Results between formulas are usually very close, within a few percent of each other.

No, BSA grows more slowly than weight because it scales roughly with the square root of the product of height and weight, not linearly with mass. This is why doubling someone's weight does not double their BSA.

No, never adjust a prescribed dose yourself. This calculator is for general reference and education; actual clinical dosing must be determined and verified by a qualified healthcare provider using validated protocols.