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Health

Body surface area

Body surface area in square metres using the Mosteller and DuBois formulas, from weight and height.

kg

In kilograms.

cm

In centimetres (1.75 m = 175 cm).

Result

Body surface area (Mosteller)
— m²
Body surface area (DuBois)
— m²

How it is calculated

Mosteller (1987): BSA (m²) = √(height (cm) × weight (kg) ÷ 3600).

DuBois (1916): BSA (m²) = 0.007184 × weight (kg)^0.425 × height (cm)^0.725.

Worked example with Mosteller: 70 kg and 175 cm. 175 × 70 = 12 250; 12 250 ÷ 3600 = 3.403; √3.403 = 1.84 m². DuBois gives 1.85 m² for the same patient.

Child example: 20 kg and 110 cm. 110 × 20 = 2200; 2200 ÷ 3600 = 0.611; √0.611 = 0.78 m².

Keep in mind

  • Support calculation: if a dose is prescribed per m² (chemotherapy, some paediatric drugs), prescribing and checking it is the job of a professional.
  • The two formulas differ little in adults of normal build; in extreme obesity and in very young children the differences grow. Use the formula your protocol specifies.
  • An average adult has around 1.7-1.9 m². A very different result is usually a unit error (metres instead of centimetres, pounds instead of kilograms).

See also

More tools in “Health”