1. What is BMI?

Definition: Body Mass Index (BMI) is a value derived from the mass (weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height.

Purpose: BMI is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults.

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

3. BMI Categories

Details: The World Health Organization (WHO) defines the following categories:

• 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 be accurate for athletes (high muscle mass), pregnant women, children, or the elderly as it doesn't distinguish between muscle and fat.

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

Q3: How often should I check my BMI?
A: Periodic checks (every few months) can help track weight changes, but daily measurements aren't necessary.

Q4: Can BMI be used for children?
A: Children's BMI is calculated differently using percentiles based on age and sex.

Q5: What if my BMI is in the overweight or obese range?
A: Consult with a healthcare professional for personalized advice on diet and exercise.