1. What is BSA and BMI?

BSA (Body Surface Area): A measurement of the total surface area of the human body, used in medical calculations.

BMI (Body Mass Index): A value derived from mass and height that categorizes underweight, normal weight, overweight, and obesity.

2. How Does the Calculator Work?

The calculator uses two formulas:

Where:

• \( BSA \) — Body Surface Area in square meters (m²)
• \( BMI \) — Body Mass Index in kg/m²
• \( W \) — Weight in kilograms (kg)
• \( H \) — Height in centimeters (cm) for BSA, meters (m) for BMI

3. Importance of BSA and BMI

BSA: Used for medication dosages, fluid requirements, and physiological measurements.

BMI: Used to screen for weight categories that may lead to health problems.

4. Using the Calculator

Tips: Enter weight in kg, height in cm for BSA calculation, and height in meters for BMI calculation. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why are there two different height inputs?
A: BSA calculation requires height in centimeters while BMI requires height in meters.

Q2: What's a normal BMI range?
A: 18.5-24.9 is considered normal weight, below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese.

Q3: What's the average BSA for adults?
A: Average BSA is about 1.7 m² for adult men and 1.6 m² for adult women.

Q4: Can I use this calculator for children?
A: The formulas work for children, but BMI interpretation is different for children and teens.

Q5: Are there limitations to these measurements?
A: Yes, BMI doesn't account for muscle mass or fat distribution. BSA formulas may vary slightly.