Body Surface Area Calculator
Calculate Body Surface Area (BSA)
About the Body Surface Area Calculator
Body surface area is a measure clinicians rely on for things like medication dosing and assessing metabolic needs, because it reflects body size better than weight alone. This calculator computes it from your weight and height using the two most established equations — DuBois and Mosteller — side by side.
Healthcare students and professionals use BSA where precise body-size scaling matters, such as chemotherapy dosing or estimating cardiac index. Showing both formulas lets you cross-check, since they can differ slightly, and gives confidence in the figure you carry forward. Students working through pharmacology or physiology exercises also find the side-by-side output useful for understanding why textbooks and references sometimes quote marginally different BSA values for the same patient.
How to Use the Body Surface Area Calculator
- Enter your weight in kilograms.
- Enter your height in centimeters.
- Read the DuBois body surface area result in square meters.
- Compare it against the Mosteller result shown alongside.
Why Use ToolForge’s Body Surface Area Calculator
- It computes both the DuBois and Mosteller formulas at once, letting you compare the two standard methods rather than trusting one.
- It reports results in square meters to two decimals, the precision clinical use expects.
- It needs only weight and height, the inputs both formulas use, keeping it simple.
- All math runs locally in your browser, so the figures stay private.
Frequently Asked Questions
What is body surface area used for?
BSA is used in medicine to scale things to body size — most notably dosing certain medications such as chemotherapy, and computing indices like cardiac output relative to body size. It often tracks physiological needs better than body weight alone.
What is the difference between the DuBois and Mosteller formulas?
Both estimate BSA from height and weight but use different equations — DuBois employs exponents on height and weight, while Mosteller uses a simpler square-root formula. They usually agree closely; showing both lets you verify the estimate.
Which BSA formula should I use?
Mosteller is popular for its simplicity and is widely used in clinical dosing, while DuBois is a long-standing standard. For most purposes they are interchangeable; follow whichever your institution or protocol specifies.
Does body surface area change if I gain or lose weight?
Yes. Because both weight and height feed the formulas, a change in weight shifts your BSA — though less dramatically than it shifts weight itself, since BSA grows slowly with size. Recalculate after a significant weight change if you are using BSA for dosing or metabolic estimates.
