BMI and BSA Calculator

BMI and BSA Formulas:

\[ BMI = \frac{Weight}{Height^2} \] \[ BSA = \sqrt{\frac{Weight \times Height}{3600}} \]

Body Mass Index (BMI):

Body Surface Area (BSA):

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1. What are BMI and BSA?

BMI (Body Mass Index) is a measure of body fat based on height and weight. BSA (Body Surface Area) is the total surface area of the human body, often used in medical calculations.

2. How Does the Calculator Work?

The calculator uses the following formulas:

\[ BMI = \frac{Weight\ (kg)}{Height^2\ (m)} \] \[ BSA = \sqrt{\frac{Weight\ (kg) \times Height\ (cm)}{3600}} \]

Where:

Weight — in kilograms (kg)
Height — in centimeters (cm) for BSA, converted to meters (m) for BMI

Explanation: BMI provides a simple numeric measure of body fatness, while BSA is important for medication dosing and medical calculations.

3. Importance of BMI and BSA

Details: BMI helps classify underweight, normal weight, overweight and obesity. BSA is used for chemotherapy dosing, renal function assessment, and other medical calculations.

4. Using the Calculator

Tips: Enter weight in kilograms and height in centimeters. All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: What are normal BMI values?
A: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obese (≥30).

Q2: Why is BSA important in medicine?
A: Many physiological processes correlate better with BSA than body weight, making it crucial for drug dosing.

Q3: What's the average BSA for adults?
A: Average is about 1.7 m² for men and 1.6 m² for women, but varies with size.

Q4: Are there limitations to BMI?
A: Yes, BMI doesn't distinguish between muscle and fat, and may not be accurate for athletes or elderly.

Q5: Which BSA formula is this calculator using?
A: This uses the Mosteller formula, the most commonly used BSA calculation in clinical practice.