Body Surface Area Calculator
Calculate body surface area (BSA) using the Mosteller, Du Bois and Haycock formulas — a standard input for clinical dosing.
Body surface area is used in clinical practice for chemotherapy and some other medicines, and to index physiological measurements. Mosteller is the usual choice because it is simple and accurate enough; Du Bois is the original 1916 formula and Haycock is preferred in children. Dosing should always follow your local protocol.
Frequently asked questions
What is body surface area used for?
BSA is used in clinical practice to scale drug doses, particularly in oncology and for some specialist medications, and to index physiological values such as cardiac output. It is calculated from height and weight.
Which BSA formula is standard?
The Mosteller formula is the most widely used because it is simple and accurate enough for routine work. The Du Bois formula is the classical one, and Haycock is preferred in paediatrics.
Is BSA the same as BMI?
No. BMI describes weight relative to height for classifying body composition, while BSA estimates total skin surface area for dosing and physiological calculations. They use the same inputs but answer different questions.
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