1. What is Body Surface Area (BSA)?

Body Surface Area (BSA) is a measurement of the total surface area of the human body. It's commonly used in medical practice to calculate drug dosages, particularly for chemotherapy drugs like methotrexate, as well as for determining physiological metrics.

2. How Does the Calculator Work?

The calculator uses the Mosteller formula:

Where:

• \( W \) — Weight in kilograms (kg)
• \( H \) — Height in centimeters (cm)

Explanation: The Mosteller formula provides a simple yet accurate way to estimate body surface area from weight and height measurements.

3. Importance of BSA Calculation

Details: BSA is crucial for determining appropriate drug dosages, especially for medications with narrow therapeutic indices like chemotherapy agents. It helps standardize doses across patients of different sizes.

4. Using the Calculator

Tips: Enter weight in kilograms and height in centimeters. Both values must be greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why use BSA for methotrexate dosing?
A: Methotrexate has a narrow therapeutic window, and dosing based on BSA helps account for individual variations in drug distribution and metabolism.

Q2: What are typical BSA values?
A: Average BSA is about 1.7 m² for adult men and 1.6 m² for adult women, but varies significantly with body size.

Q3: How accurate is the Mosteller formula?
A: It's accurate to within 1-2% of more complex calculations and is widely used in clinical practice.

Q4: Are there other BSA formulas?
A: Yes, other formulas include DuBois & DuBois, Haycock, and Gehan & George, but Mosteller is simplest and sufficiently accurate.

Q5: When should BSA not be used for dosing?
A: For obese patients or those with extreme body compositions, alternative dosing methods may be needed.