Body Surface Area (BSA) is a measure used to standardize drug dosing — especially chemotherapy — across patients of different sizes. It is expressed in square meters (m²) and calculated from height and weight.
Calculate Body Surface Area
How to Use the BSA Calculator
The body surface area calculator computes BSA using two formulas. Enter height and weight in metric or imperial units. Results are shown in m² for both Mosteller (recommended for oncology) and DuBois formulas.
Typical BSA Values
Average adult male BSA is approximately 1.9 m²; average adult female is 1.6 m². Pediatric BSA is significantly lower — a 10kg child has BSA of approximately 0.46 m². Always use the BSA formula specified in the drug prescribing information or institutional protocol.
Frequently Asked Questions
Is this BSA calculator free?
Yes, completely free with no signup required.
What is the Mosteller formula for BSA?
Mosteller: BSA (m²) = √(height_cm × weight_kg / 3600). This is the most commonly used formula in oncology and is the simplest to calculate. It gives results very close to the more complex DuBois formula.
When is BSA used clinically?
BSA is used for chemotherapy dosing (to normalize toxic drug exposure across body sizes), cardiac index calculation (cardiac output normalized to BSA), and some other medication dosing where weight alone is insufficient. It is particularly important in pediatric and oncology settings.
Which BSA formula should I use?
The Mosteller formula is the most widely used in modern oncology and clinical practice. The DuBois formula was the original (1916) and historically common. Both produce results within 3-5% of each other for most adults. Check your institution's protocol for the preferred formula.