CalcBrew

Body Surface Area Calculator

Calculate body surface area (BSA) with the Mosteller formula from height and weight. Used e.g. for drug dosing.

By Miikka · CalcBrew · Updated

20.6 sq ft

Body surface area

BSA (Mosteller)20.6 sq ft
ℹ️ Mosteller formula: BSA = √(height_cm × weight_kg / 3600). Typical adult BSA ~1.7 m².
Share:

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

Cite this calculator
APACalcBrew. (2026). Body Surface Area Calculator. https://calcbrew.com/body-surface-area-calculator
MLA“Body Surface Area Calculator.” CalcBrew, 2026, calcbrew.com/body-surface-area-calculator.

Link to https://calcbrew.com/body-surface-area-calculator. Results are estimates; cite the underlying formula or data source for academic work.

Related tools

Calorie CalculatorPopularDaily calorie needs (TDEE) and basal metabolic rate (BMR).Calorie Deficit CalculatorCalculate the daily calorie deficit needed for a target weekly weight loss and your goa…Child Height Predictor — Adult HeightEstimate your child's adult height from parents' heights.Due Date CalculatorCalculate due date, pregnancy weeks and important milestones.Fiber Intake CalculatorCalculate your daily fiber needs based on calorie intake and compare to the recommendat…HbA1c CalculatorConvert your long-term blood sugar (HbA1c) into estimated average glucose in mmol/L and…

More in Health & Nutrition · All calculators