Body Surface Area Calculator
Du Bois and Mosteller formulas
Reviewed by the Nutricity editorial teamLast updated:
Calculator
How it is calculated
Two common formulas are shown:
- Du Bois: BSA = 0.007184 × W0.425 × H0.725
- Mosteller: BSA = √((H × W) / 3600)
Both use weight in kg and height in cm and return BSA in m².
How to interpret the result
For an adult of average build, BSA is typically around 1.6–1.9 m². The two formulas usually agree within a few percent; Mosteller is often preferred for simplicity, while Du Bois is the classic reference.
When it is used
BSA is used to normalise drug doses (e.g. chemotherapy), cardiac index and some nutritional calculations. For related body-composition tools see BMI, body fat % and ideal weight.
Limitations
- Both formulas are estimates and may be less accurate at extremes of weight.
- Drug dosing should always follow the specific protocol and be reviewed by a clinician.
- This tool is for reference, not clinical decision-making.
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Frequently asked questions
What is body surface area used for?
It is used to normalise drug doses, cardiac output and some metabolic calculations in clinical practice.
Which formula is better?
Mosteller is simpler and widely used; Du Bois is the classic formula. They usually agree closely.
Can I use this for drug dosing?
Only as a reference. Drug dosing must follow the specific protocol and be verified by a clinician.