Body Surface Area (BSA) Calculator
BSA by the Mosteller formula
Equation & limitations
- Equation
- BSA (m²) = √(height (cm) × weight (kg) / 3600)
- Version
- Mosteller 1987
- Source
- Mosteller RD. Simplified calculation of body-surface area. N Engl J Med. 1987;317:1098.
- Appropriate in
- Adults and children (validated over a wide size range).
- Limitations
- An estimate; other formulae (Du Bois, Haycock) can differ by a few percent, especially at the extremes.
- Not validated for oedematous/fluid-overloaded patients in whom weight overestimates tissue mass.
For educational use. Results support, and do not replace, clinical judgement — check them against the patient and local guidelines.