BSA by formula
The formulas agree closely for most adults.
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Body Surface Area Calculator
Estimate your body surface area (BSA) in square metres from height and weight, using the Mosteller, Du Bois, and Haycock formulas.
Body surface area (Mosteller)
1.93 m²
Du Bois—
Haycock—
Average—
How it works
Body surface area is used in medicine to size drug doses (especially chemotherapy), estimate metabolic rate, and assess burns. It is derived from height and weight using empirical formulas. The Mosteller formula is the most common because it is simple and accurate.
Mosteller: BSA = √(height(cm) × weight(kg) ÷ 3600)
Du Bois: BSA = 0.007184 × height^0.725 × weight^0.425
Haycock: BSA = 0.024265 × height^0.3964 × weight^0.5378
Du Bois: BSA = 0.007184 × height^0.725 × weight^0.425
Haycock: BSA = 0.024265 × height^0.3964 × weight^0.5378
An average adult BSA is roughly 1.7 m² for women and 1.9 m² for men.
Frequently asked questions
Which BSA formula should I use?
Mosteller is the default in most clinical settings because it is easy and reliable. Du Bois is the historical standard, and results differ only slightly.
Why is BSA used for drug dosing?
BSA correlates with blood volume and metabolic rate better than weight alone, so it can give a more consistent dose across body sizes for certain medicines.