Body Surface Area Calculator
Calculate body surface area (BSA) from height and weight with the Mosteller, Du Bois and Haycock formulas.
cm
ftin
lb
—
For healthy adults. These are estimates, not medical advice. Ask a doctor or dietitian about your own targets — especially if you are pregnant, have a health condition or are under 18.
BSA formulas
Mosteller: BSA (m²) = √(height (cm) × weight (kg) ÷ 3600)
Du Bois: BSA = 0.007184 × weight^0.425 × height^0.725
Du Bois: BSA = 0.007184 × weight^0.425 × height^0.725
Example: 175 cm and 75 kg give √(175 × 75 ÷ 3600) = 1.91 m².
Where BSA is used
Doctors use body surface area to dose some medicines, such as chemotherapy, and to index measurements like cardiac output. An average adult has about 1.7–2.0 m².
Frequently asked questions
How do I calculate body surface area?
With the Mosteller formula: multiply height in cm by weight in kg, divide by 3600 and take the square root.
What is a normal body surface area?
Around 1.9 m² for adult men and 1.6–1.7 m² for adult women on average.