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: BMI is used to screen for weight categories that may lead to health problems but is not diagnostic of body fatness or health.

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: Weight in kilograms is divided by the square of height in meters.

3. BMI Categories

Details:

• Underweight: BMI < 18.5
• Normal weight: BMI 18.5-24.9
• Overweight: BMI 25-29.9
• 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 (high muscle mass) or elderly (loss of muscle mass).

Q2: How do I convert pounds to kilograms?
A: Multiply pounds by 0.453592 to get kilograms.

Q3: How do I convert feet/inches to meters?
A: Multiply feet by 0.3048 and inches by 0.0254, then sum them.

Q4: Why is BMI used if it has limitations?
A: It's a simple, inexpensive screening tool that correlates with more direct measures of body fat.

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentile charts.