Body Surface Area Calculator
Calculate body surface area (BSA) with the Mosteller formula from height and weight. Used e.g. for drug dosing.
1.91 m²
Body surface area
| BSA (Mosteller) | 1.91 m² |
A body surface area calculator (BSA) estimates the total area of your skin in square metres from your height and weight. BSA is widely used in healthcare, for example in drug dosing, because it describes body size more comprehensively than weight alone.
How the calculator works and what it’s for▾
The Mosteller formula
The calculator uses the Mosteller formula: BSA equals the square root of height in centimetres multiplied by weight in kilograms and divided by 3600.
For example, 175 cm and 70 kg give a surface area of about 1.84 m². A typical adult BSA is around 1.7 m².
What you enter and what you get
You enter your height in centimetres and your weight in kilograms. The calculator returns your body surface area in square metres, computed with the Mosteller formula.
Mosteller is popular precisely for its simplicity and solid accuracy, and it is used widely in clinical practice.
What BSA is used for
The dose of many medicines, especially chemotherapy drugs, is scaled to body surface area rather than weight alone. This keeps dosing more consistent across patients of different sizes.
BSA is also used, for example, when assessing heart function and fluid balance, where values are scaled to body size.
Good to know
The calculator provides an estimate, not a precise measurement. Different formulas (such as Du Bois) yield slightly different results.
Drug dosing always belongs to a professional. Use the calculator for illustration, not as a basis for treatment decisions.
🔄 Reviewed June 2026
Frequently asked questions
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