What is body surface area used for?

Body surface area (BSA) estimates the total external surface of the body, in square meters. It is most familiar as an input some clinical dosing calculations use, and as a reference measure in some physiology and burn-assessment contexts.

What is the Mosteller formula?

Mosteller is the simpler and more commonly cited BSA formula today: the square root of (height in cm times weight in kg, divided by 3600). It was published in 1987 as an easier-to-remember alternative to Du Bois.

What is the Du Bois formula?

Du Bois is the older, historically standard BSA formula, published in 1916: 0.007184 times height in cm to the 0.725 power, times weight in kg to the 0.425 power. Many reference charts still cite it alongside or instead of Mosteller.

Should I use this to calculate a medication dose?

No. This calculator is for general education only. Clinical dosing that uses BSA must be calculated and verified by a qualified healthcare professional using validated clinical tools, never a general consumer calculator.

Body Surface Area Calculator

Body surface area (BSA) estimates the total external surface of the body from height and weight, in square meters. This calculator compares the two most commonly cited formulas — Mosteller and Du Bois — side by side.

For general education only. Clinical uses of BSA require a qualified healthcare professional using validated clinical tools.

Calculate your BSA

Enter metric measurements. Runs entirely in your browser.

The two formulas

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

Du Bois: BSA (m²) = 0.007184 × height (cm)^0.725 × weight (kg)^0.425

The two formulas typically agree within a small margin for adults of typical build; they can diverge more at unusual heights or weights.

How BSA is used

BSA appears in some clinical dosing calculations, physiology reference values, and burn-assessment scales. None of those uses should be replicated from a general consumer calculator — this tool is for general education, and any clinical decision needs a qualified healthcare professional using validated clinical tools and current guidance.

Common questions

What is body surface area used for?: Body surface area (BSA) estimates the total external surface of the body, in square meters. It is most familiar as an input some clinical dosing calculations use, and as a reference measure in some physiology and burn-assessment contexts.
What is the Mosteller formula?: Mosteller is the simpler and more commonly cited BSA formula today: the square root of (height in cm times weight in kg, divided by 3600). It was published in 1987 as an easier-to-remember alternative to Du Bois.
What is the Du Bois formula?: Du Bois is the older, historically standard BSA formula, published in 1916: 0.007184 times height in cm to the 0.725 power, times weight in kg to the 0.425 power. Many reference charts still cite it alongside or instead of Mosteller.
Should I use this to calculate a medication dose?: No. This calculator is for general education only. Clinical dosing that uses BSA must be calculated and verified by a qualified healthcare professional using validated clinical tools, never a general consumer calculator.

Body Surface Area Calculator

Calculate your BSA

The two formulas

How BSA is used

Common questions

Related calculators