1. What is BMI?

Definition: Body Mass Index (BMI) is a value derived from the mass (weight) and height of a person.

Purpose: The BMI is a simple, inexpensive screening method for weight category—underweight, healthy weight, overweight, and obesity.

2. How Does the BMI Calculator Work?

The calculator uses the formula:

Where:

• \( BMI \) — Body Mass Index (kg/m²)
• \( W \) — Weight (kilograms)
• \( H \) — Height (meters)

Explanation: The weight in kilograms is divided by the square of height in meters.

3. BMI Categories

Details:

• Underweight: BMI less than 18.5
• Normal weight: BMI 18.5 to 24.9
• Overweight: BMI 25 to 29.9
• Obesity: BMI 30 or greater

4. Using the Calculator

Tips: Enter your weight in kilograms and height in meters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Is BMI accurate for everyone?
A: BMI may not be accurate for athletes (high muscle mass), pregnant women, or the elderly.

Q2: What's the difference between kg/m² and lb/in²?
A: The standard BMI formula uses metric units. For imperial units, multiply weight in pounds by 703 and divide by height in inches squared.

Q3: Why is BMI important?
A: BMI is a quick screening tool that can indicate potential weight problems that may lead to health issues.

Q4: What should I do if my BMI is outside the normal range?
A: Consult with a healthcare professional for personalized advice regarding diet and exercise.

Q5: How often should I check my BMI?
A: Periodic checks (every few months) can help track changes, but daily fluctuations are normal.