1. What is Body Mass Index (BMI)?

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

Purpose: It's used to categorize whether a person is underweight, normal weight, overweight, or obese based on tissue mass (muscle, fat, and bone) and height.

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 to calculate the BMI value.

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 is a useful screening tool but doesn't directly measure body fat. It may not be accurate for athletes with high muscle mass or elderly with lost muscle mass.

Q2: How do I convert pounds to kilograms?
A: 1 pound = 0.453592 kilograms. Multiply your weight in pounds by 0.453592 to get kilograms.

Q3: How do I convert feet/inches to meters?
A: 1 foot = 0.3048 meters, 1 inch = 0.0254 meters. For example, 5'7" = (5×0.3048) + (7×0.0254) = 1.7018 meters.

Q4: What's a healthy BMI range?
A: For most adults, a healthy BMI is between 18.5 and 24.9.

Q5: Should children use this calculator?
A: BMI interpretation for children and teens is different, considering age and sex-specific percentiles.