Body Surface Area Calculator
Mosteller & DuBois Formulas
Enter your height and weight to calculate your Body Surface Area (BSA) in square meters.
Parameters
Body Surface Area (Mosteller)
| Mosteller Formula | -- |
| DuBois Formula | -- |
Understanding Body Surface Area (BSA)
Body Surface Area (BSA) is the total surface area of the human body, most commonly used clinically for medication dosing (especially chemotherapy), burn severity assessment, and calculating certain cardiac and kidney function indices.
Medication Dosing
Many chemotherapy drugs and other medications are dosed per square meter of BSA rather than by weight alone, since BSA correlates well with metabolic mass.
Burn Assessment
Clinicians use BSA percentage (like the "Rule of Nines") to estimate burn severity and guide fluid resuscitation.
Cardiac Index
BSA is used to normalize cardiac output into "cardiac index," allowing fair comparison of heart function across people of different sizes.
Formula Choice
Mosteller (1987) is simpler and widely used today; DuBois (1916) is the historical original, still referenced in some clinical contexts.
The Mosteller Formula
The Mosteller formula is the most widely used BSA equation today due to its simplicity and accuracy across a wide range of body sizes.
Comparing the Two Formulas
| Formula | Year | Notes |
|---|---|---|
| Mosteller | 1987 | Simple square-root formula, most widely used today |
| DuBois | 1916 | The original clinical BSA formula, still referenced historically |
Important Limitations
- A clinical reference, not a wellness metric: BSA is primarily used for medical dosing calculations, not general fitness tracking.
- Formula variance: Different BSA formulas can produce slightly different results — clinical settings specify which formula to use.
- Never self-dose medication: Real medication dosing must always be calculated and verified by a licensed clinician or pharmacist.
Key Takeaways
- BSA is a clinical measurement. It's used for medication dosing, burn assessment, and cardiac/kidney indices — not general body composition tracking.
- Mosteller is the modern standard. It's simpler to compute and widely adopted, though DuBois remains historically referenced.
- Height and weight only. Unlike some body composition tools, BSA doesn't require age, sex, or circumference measurements.
- Consult a professional. BSA is used clinically for medication dosing and burn assessment — never adjust or interpret a real medical dosage without your physician or pharmacist.