How it works
Body surface area (BSA) is the total area of the skin, in square meters. Clinicians use it to dose some medications, especially chemotherapy, and to index measurements like cardiac output to body size.
The Mosteller formula (1987) is the simplest and is widely used in hospitals. The older DuBois formula (1916) remains common; Haycock and Gehan-George are often used for children. For typical adults they agree within a few hundredths of a square meter.
An average adult BSA is about 1.9 m² for men and 1.6 m² for women. Results are estimates, not medical advice.
Formula
Mosteller: BSA = √(height cm × weight kg ÷ 3600) · DuBois: BSA = 0.007184 × kg^0.425 × cm^0.725
Questions people ask
What is a normal body surface area?
Around 1.9 m² for adult men and 1.6 m² for adult women on average, with a typical adult range of about 1.5 to 2.2 m².
Which BSA formula should I use?
Mosteller is the most common in clinical practice because it is simple and accurate for adults. Your care team or protocol may specify a particular formula.
Why is BSA used for drug dosing?
Some drugs have a narrow range between effective and toxic doses. BSA tracks metabolic rate and blood volume more closely than weight alone, so it helps scale doses across body sizes.