Body Surface Area (BSA) Calculator
Calculate BSA from height and weight using the Du Bois or Mosteller formula.
Body surface area is used to dose chemotherapy and some other medications, to index cardiac output and other measurements (e.g., cardiac index), and in some kidney function calculations. Average adult BSA is roughly 1.7 m².
Not a dosing recommendation. Medication dosing by BSA should always be confirmed by a pharmacist or prescriber using the specific protocol for that drug.
How BSA is calculated
Height in cm, weight in kg, result in m² for both formulas.
Common questions
BSA is used to calculate doses for chemotherapy and certain other medications, to index measurements like cardiac output (giving cardiac index), and as an input in some clinical equations. It’s considered a better proxy than weight alone for how a drug distributes through the body in many contexts.