1. What is BMI?

Definition: Body Mass Index (BMI) is a value derived from the mass and height of a person, providing a simple numeric measure of body fatness.

Purpose: It's a screening tool to identify possible weight problems in adults, though it doesn't directly measure body fat.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

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

3. BMI Categories

Details:

• Underweight: BMI < 18.5
• Normal weight: 18.5 ≤ BMI < 25
• Overweight: 25 ≤ BMI < 30
• Obesity: BMI ≥ 30

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 accurately reflect body fat in athletes (who have more muscle) or elderly (who may have lost muscle).

Q2: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy.

Q3: Can children use this calculator?
A: No, children need age- and sex-specific BMI percentiles.

Q4: Why use metric units?
A: Metric units simplify the calculation as they're already in the standard BMI units (kg/m²).

Q5: What if I know my height in centimeters?
A: Convert to meters by dividing by 100 (e.g., 175 cm = 1.75 m).