Body Surface Area Calculator

How to Calculate Body Surface Area

Body Surface Area (BSA) is an estimate of the total surface area of the human body. It's widely used in medicine for various purposes, including determining drug dosages and assessing metabolic needs.

The DuBois and DuBois Formula

The most commonly used formula for calculating BSA is the DuBois and DuBois formula:

$$BSA = 0.007184 \times W^{0.425} \times H^{0.725}$$

Where:

• BSA = Body Surface Area in square meters (m²)
• W = Weight in kilograms (kg)
• H = Height in centimeters (cm)

Calculation Steps

1. Measure your weight in kilograms and height in centimeters.
2. Substitute these values into the formula.
3. Perform the calculations:
   • Raise weight to the power of 0.425
   • Raise height to the power of 0.725
   • Multiply these results together
   • Multiply the product by 0.007184
4. The result is your BSA in square meters.

Example Calculation

Let's calculate the BSA for someone with the following measurements:

• Weight: 70 kg
• Height: 170 cm

Substituting these values into the formula:

$$\begin{align} BSA &= 0.007184 \times 70^{0.425} \times 170^{0.725} \\ &= 0.007184 \times 4.9540 \times 38.5456 \\ &= 1.80\;m² \end{align}$$

Therefore, the Body Surface Area for this person is approximately 1.80 m².

Visual Representation

This bar chart compares the example BSA calculation (1.80 m²) with the typical adult BSA range (average of 1.75 m²). It visually demonstrates how the calculated BSA relates to the average adult range.