Body Surface Area (BSA) Calculator: Mosteller, DuBois & Haycock
Calculate body surface area with three standard formulas from height and weight.
✓ Formulas cited from the published literature
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Results
About this calculator
Body surface area (BSA) is used to normalise measurements and doses to body size. It is used for chemotherapy dosing, cardiac index, GFR indexing (mL/min/1.73 m²) and burn assessment. The three formulas agree closely for typical adults.
How it works
Mosteller = √(height cm × weight kg ÷ 3600)
DuBois = 0.007184 × W0.425 × H0.725
Haycock = 0.024265 × W0.5378 × H0.3964
W = weight in kg, H = height in cm.
How to read your result
The average adult BSA is roughly 1.7 m² (1.9 m² for men and 1.6 m² for women). Differences between formulas are usually under 0.05 m², but can widen at extremes of size.
Worked example
An adult weighing 70 kg and 175 cm tall.
| Mosteller | 1.84 m² Most widely used clinically |
| DuBois & DuBois | 1.85 m² |
| Haycock | 1.85 m² Often used in children |
Frequently asked questions
Which BSA formula is best?
Mosteller is the most widely adopted because it is simple and accurate for adults. Haycock is often preferred for neonates and children.
Why is BSA used for dosing?
Many drugs scale better with surface area than with weight, particularly cytotoxics.
What is a normal BSA?
Around 1.9 m² in adult men and 1.6 m² in adult women.
Limitations and when not to use
Does not account for obesity or body composition. Institutional dosing policies take precedence.
Sources and references
- Mosteller RD. Simplified calculation of body-surface area. N Engl J Med 1987;317:1098.
- Du Bois D, Du Bois EF. A formula to estimate the approximate surface area. Arch Intern Med 1916;17:863–871.
- Haycock GB, et al. Geometric method for measuring body surface area. J Pediatr 1978;93:62–66.
Last updated: 2026-10-09