For educational and tracking purposes only. Results are estimates and are not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional.
Calculator tool
How this calculator works
Use the explanation to understand the formula, assumptions, and practical limits behind the calculator result.
What BSA Means
Body surface area (BSA) estimates the body's external area in square meters. Some clinical workflows use it for drug dosing, fluid calculations, and burn assessment, which is why the unit must be handled carefully.
Formulas Used Here
The calculator reports the Mosteller estimate as the main result and also shows Du Bois:
Why Two Results Differ
Both formulas are estimates built from height and weight, but they were derived differently. Small differences between them are expected; the correct choice depends on the clinical protocol being followed.
Do Not Treat BSA as Self-Dosing Advice
This calculator can check arithmetic, but it cannot decide a medication dose, protocol, or safety margin. Clinical use should follow the prescribing source and licensed professional review.
Frequently asked questions
Which BSA result should I use?
Use the formula required by the clinical protocol or medication reference you are following. The calculator shows both because different settings may specify different formulas.
Why is BSA measured in square meters?
Because it estimates body surface area, not body weight or volume. Square meters are the standard clinical unit for that surface-area measure.
Can I use BSA alone to choose a medication dose?
No. BSA may be one input, but dosing can also depend on the drug, organ function, labs, age, protocol, and clinical judgment.
Why do height and weight need consistent units?
Because the formulas expect centimeters and kilograms. Using inches or pounds without converting first would produce the wrong BSA.
