Calculyn

Body Surface Area Calculator

Calculate body surface area (BSA) with the Mosteller formula.

cm
kg

Results update as you type.

Body surface area (Mosteller)

1.84m²
Du Bois formula
1.85m²
Body surface area (Mosteller)1.84

Educational estimate only — not for medical dosing decisions.

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Quick answer

175 cm and 70 kg → √(175 × 70 ÷ 3600) = 1.84 m².

How it works

BSA is used in medicine to dose some drugs and index heart measurements. The average adult is around 1.7–1.9 m².

Formula

BSA (m²) = √(height cm × weight kg ÷ 3600)

Assumptions & limitations

  • Metric inputs (cm, kg)

Formula and assumptions reviewed October 2026 by the Calculyn team. How we build our calculators

Frequently asked questions

Which formula is best?

Mosteller is the most common for its simplicity; Du Bois gives very similar results for adults.