Body Surface Area Calculator

Height and weight — calculate BSA using the Mosteller formula.

Weight

Height (ft)

Height (in)

Body surface area

1.94 m²

Uses the Mosteller formula, the most widely used BSA estimate in clinical practice — often used for medication dosing (especially chemotherapy) and cardiac index calculations. Always defer to a clinician's dosing decision, not a calculator.

A worked example

A person at 170 lb and 5'9" has an estimated BSA of about 1.94 m² — close to the commonly cited average adult value of roughly 1.7-2.0 m².

Frequently asked questions

Why does BSA matter for medication dosing?

Some medications, especially chemotherapy drugs, are dosed per square meter of body surface rather than by weight alone, since BSA correlates well with blood volume, cardiac output, and other physiological factors relevant to how a drug distributes through the body.

Why the Mosteller formula specifically?

It's simpler to calculate than alternatives like the DuBois formula while producing very similar results for most adults, which is why it's widely used in clinical practice today.

This calculator provides estimates for general informational purposes only and is not medical advice. Medication dosing must always be determined by a qualified healthcare professional.