1. What is Body Surface Area (BSA)?

Definition: BSA is the measured or calculated surface area of the human body, used in many medical measurements including drug dosage calculations.

Purpose: It provides a more accurate indicator of metabolic mass than body weight alone, as many physiological processes correlate better with body surface area.

2. How Does the Mosteller Formula Work?

The calculator uses the Mosteller formula:

Where:

• \( BSA \) — Body Surface Area (square meters)
• \( W \) — Weight (kilograms)
• \( H \) — Height (centimeters)

Explanation: The formula calculates BSA by taking the square root of the product of weight and height divided by 3600.

3. Importance of BSA Calculation

Details: BSA is used to calculate drug dosages for chemotherapy, estimate glomerular filtration rate (GFR), and determine cardiac index among other medical applications.

4. Using the Calculator

Tips: Enter the patient's weight in kilograms and height in centimeters. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why use BSA instead of weight for drug dosing?
A: Many physiological processes correlate better with body surface area than body weight alone, making BSA more accurate for certain medications.

Q2: What are other BSA formulas?
A: Other common formulas include DuBois & DuBois, Haycock, and Boyd, but Mosteller is simplest and most widely used.

Q3: How accurate is the Mosteller formula?
A: It's accurate within 1-2% of more complex formulas and is the recommended formula by many medical organizations.

Q4: When is BSA not appropriate for dosing?
A: For drugs with narrow therapeutic indices or those primarily distributed in body water, weight-based dosing may be preferred.

Q5: What's a normal BSA range?
A: Average BSA is about 1.7 m² for adult men and 1.6 m² for adult women, but varies significantly with body size.