Body surface area calculator (BSA)
Calculate body surface area (BSA) with the Mosteller formula, from height and weight. BSA is commonly used to dose some drugs and to normalize physiological indices.
Estimated BSA
Enter the values to see the result.
This tool assists calculation. It does not replace clinical judgement and is not a treatment instruction. Check against your institution protocol, reference ranges, and prescribing information. Clinical decisions belong to the treating clinician.
Formula
BSA = square root of (Height(cm) × Weight(kg) / 3600). This is the Mosteller formula, one of the most widely used BSA formulas.
Frequently asked questions
Why the Mosteller formula?
Mosteller is one of the simplest and most common BSA formulas. Other formulas (such as Du Bois) give close estimates.
What is BSA used for?
BSA is often used to dose some drugs (for example chemotherapy) and to normalize indices such as cardiac index.