Body Surface Area Calculator

BSA Du Bois (m²)

BSA Mosteller (m²)

BSA Haycock (m²)

About Body Surface Area Calculator

What Is Body Surface Area?

Body Surface Area (BSA) is the measured or calculated surface area of a human body expressed in square meters. It is a more accurate indicator of metabolic mass than body weight alone because it correlates better with many physiological functions. BSA is critically important in medicine for calculating chemotherapy drug doses, determining cardiac output index, estimating burn severity, and calibrating renal clearance measurements. The average adult BSA is approximately 1.7 m2, though this varies significantly based on height and weight.

BSA Formulas Used

This calculator provides results from three validated formulas. The Du Bois formula (1916): BSA = 0.007184 x height^0.725 x weight^0.425. The Mosteller formula (1987): BSA = sqrt(height x weight / 3600). The Haycock formula (1978): BSA = 0.024265 x height^0.3964 x weight^0.5378. The Mosteller formula is widely preferred for its simplicity and adequate accuracy in most clinical situations.

How to Use This Calculator

Enter your height and weight in your preferred units. The calculator instantly displays your BSA using all three formulas so you can compare results. It also shows common clinical applications such as the cardiac index (cardiac output / BSA) and how BSA-based dosing differs from weight-based dosing for reference.

Frequently Asked Questions

Why is BSA used for drug dosing?

BSA correlates better with organ size, blood volume, and metabolic rate than weight alone. This makes it more accurate for dosing drugs with narrow therapeutic windows, particularly chemotherapy agents.

What is the average BSA for adults?

Average BSA is approximately 1.7 m2 for adults. Men average around 1.9 m2 and women around 1.6 m2. Values vary significantly with body size.

Which formula should I use?

The Mosteller formula is most commonly used in clinical practice due to its simplicity. For pediatric patients, the Haycock formula is preferred. All formulas produce similar results for average-sized adults.