Body Surface Area (BSA)
Calculate BSA using Mosteller, DuBois, or Haycock formulas for BSA-dosed drugs like chemotherapy.
Body Surface Area is used to dose drugs — most notably chemotherapy — where dosing per kilogram isn't accurate enough and dosing is instead expressed per m² of body surface. See How Calculator Tools Work for the shared layout.
Inputs
- Weight (kg)
- Height (cm)
- Formula — Mosteller (default), DuBois, or Haycock
The three formulas
The tool calculates all three simultaneously and shows your selected one as the primary result, so you can compare:
| Formula | Equation |
|---|---|
| Mosteller | √((height × weight) / 3600) |
| DuBois | 0.007184 × height^0.725 × weight^0.425 |
| Haycock | 0.024265 × height^0.3964 × weight^0.5378 |
Mosteller is the default and the most commonly used in practice; DuBois and Haycock are shown alongside it for comparison or where a specific protocol calls for one of them by name.
Below 3 kg, all three formulas lose accuracy — for very small infants, treat the result as an estimate and consult a paediatric specialist rather than dosing purely off the calculated BSA.