Body Surface Area (BSA) Calculator
Body surface area (BSA) is used for chemotherapy and other weight-sensitive drug dosing. This calculator uses the Mosteller and DuBois formulas from height and weight.
Quick answer
Body surface area (BSA) is used to dose chemotherapy and some other drugs. The Mosteller formula is BSA (m²) = √(height in cm × weight in kg ÷ 3600); the Du Bois formula is BSA = 0.007184 × weight^0.425 × height^0.725. Mosteller is the most common because it is simple to compute.
Height & weight
How to use the Body Surface Area calculator
- 1Enter height and weight. Enter height and weight in metric or imperial units.
- 2Read both BSA estimates. The tool shows the Mosteller and Du Bois body surface area in square metres (m²).
- 3Use it for dosing with a professional. BSA-based dosing decisions, especially for chemotherapy, belong to an oncology or clinical team.
Medical disclaimer: This is general health information, not medical advice. It does not diagnose or treat any condition, and the results are estimates based on public reference formulas. Always consult a qualified doctor about your individual health. If you think you may have a medical emergency, contact your local emergency services immediately.
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Book a consultationFrequently asked questions
Which BSA formula should I use?⌄
Mosteller is the most widely used in oncology because it is simple and accurate enough for dosing. Du Bois is the classic original. They usually agree closely. This tool shows both.
Why is body surface area used for chemotherapy dosing?⌄
Dose per square metre of body surface area scales better with metabolism and blood volume than dose per kilogram, which is why many chemotherapy and some other drug doses are expressed per m².
Is the BSA calculation exact?⌄
It is an estimate from height and weight. Actual prescribing always rests with the treating clinical team.
Sources & validation
This calculator reproduces the published Body Surface Area score, validated for body surface area for weight-/BSA-based drug dosing.
- Mosteller RD. Simplified calculation of body-surface area (NEJM 1987;317:1098): BSA(m²)=√(height[cm]×weight[kg]/3600) — verified 2026-06-18
- Du Bois D, Du Bois EF. A formula to estimate the approximate surface area if height and weight be known (Arch Intern Med 1916;17:863-871): BSA=0.007184×W^0.425×H^0.725 — verified 2026-06-18
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