Body Surface Area Calculator
Body surface area in m² (Mosteller and DuBois formulas) — reference only
Frequently Asked Questions
Body surface area (BSA) — the total external surface area of a person's body — is used clinically for tasks like dosing certain medications and assessing burn severity, and this calculator specifically exists as a reference tool showing two commonly used estimation formulas side by side, since they can produce slightly different results.
Why two formulas, and why they can disagree
The Mosteller formula and the DuBois & DuBois formula are both established methods for estimating BSA from height and weight, developed through different research approaches and at different points in medical history — Mosteller is mathematically simpler and widely used in modern clinical contexts, while DuBois & DuBois, an older formula, remains a common reference point that some clinical protocols still specify by name. For the same height and weight inputs, the two formulas typically produce results that are close but not identical, since they're derived from different underlying datasets and mathematical approaches to the same estimation problem.
A worked example
The same person's height and weight run through both formulas will generally produce two BSA estimates within a small range of each other, close enough that either is a reasonable general estimate, but different enough that a specific clinical protocol specifying "Mosteller" versus "DuBois" isn't an arbitrary choice — if a medical context calls for one formula specifically, using the other could produce a meaningfully different dosing calculation downstream.
How this connects to your other health calculations
This calculator is explicitly a reference tool, not a substitute for clinical guidance — any BSA-based medication dosing or clinical decision should be made by a qualified healthcare provider using their own protocol's specified formula, not a general-purpose online calculator. For general body composition context alongside BSA, BMI and the Body Fat Calculator provide related but distinct measures.
Common mistakes
Treating this calculator's output as clinically authoritative for an actual medical dosing decision, rather than as a general reference figure, is the most important thing to avoid — always defer to a healthcare provider's specific formula choice and clinical judgment for any decision where BSA accuracy actually matters medically.