BMI Calculator - Body Mass Index And BSA

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 is 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 these 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

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 to calculate drug dosages and medical indicators. More accurate than body weight alone for many medical purposes.

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 overweight, and 30+ obese.

Q2: Why is BSA important in medicine?
A: Many physiological processes correlate better with BSA than body weight. Used for chemotherapy dosing, renal function assessment, and more.

Q3: Are there limitations to BMI?
A: Yes, it doesn't distinguish between muscle and fat. Athletes may have high BMI without excess fat.

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

Q5: Should BMI be interpreted differently for different populations?
A: Yes, some ethnic groups may have different health risks at the same BMI levels.