Calculator
Body Surface Area
Estimates body surface area (m²) from height and weight using Mosteller, DuBois and Costeff. Informational only; clinical decisions such as drug dosing belong to a physician.
Frequently asked questions
What is body surface area used for?
BSA estimates the total external surface of the body in m². Some drug doses, fluid calculations and clinical assessments use BSA instead of weight. This tool is informational; dosing decisions belong to a clinician.
Which method is most accurate?
Mosteller is the most common and practical. DuBois is a classic reference; Costeff is used in children (Child Metrics uses it). The three usually agree closely.
Why three values?
For transparency we show all three formulas and their average. Notable differences, common at very low weights, are flagged.