Calculate 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:

\( Weight \) — Body weight in kilograms
\( Height \) — For BMI: height in meters; For BSA: height in centimeters

3. Importance of BMI and BSA

BMI: Used to classify underweight, normal weight, overweight, and obesity. Helps assess health risks associated with weight.
BSA: Used in medical settings for drug dosing, chemotherapy regimens, and other clinical 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 is a healthy 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.

Q2: Why is BSA important in medicine?
A: Many medications, especially chemotherapy drugs, are dosed based on BSA to ensure proper distribution throughout the body.

Q3: Are there limitations to BMI?
A: BMI doesn't distinguish between muscle and fat, so athletes may have high BMI without excess fat. It also doesn't account for fat distribution.

Q4: Which BSA formula is this calculator using?
A: This uses the Mosteller formula, which is the most commonly used BSA calculation method.

Q5: Should BMI be interpreted differently for children?
A: Yes, children's BMI is interpreted using age- and sex-specific percentiles rather than the adult categories.