1. What is BMI?

Body Mass Index (BMI) is a person's weight in kilograms divided by the square of height in meters. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age according to CDC guidelines.

2. How Does the Calculator Work?

The calculator uses the BMI formula:

Where:

• \( weight \) — Body weight in kilograms (kg)
• \( height \) — Height in meters (m)

Explanation: The equation calculates body mass index which is a screening tool for weight categories that may lead to health problems.

3. Importance of BMI Calculation

Details: BMI is an inexpensive and easy screening method for weight category—underweight, healthy weight, overweight, and obesity. For children, BMI percentile is the preferred assessment method.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For children, the result should be plotted on CDC growth charts.

5. Frequently Asked Questions (FAQ)

Q1: How is BMI interpreted for children?
A: For children, BMI is plotted on CDC growth charts to determine the corresponding BMI-for-age percentile.

Q2: What are the BMI categories for children?
A: Underweight (<5th percentile), Healthy weight (5th-85th percentile), Overweight (85th-95th percentile), Obese (≥95th percentile).

Q3: Why use BMI for children?
A: BMI-for-age is the recommended measure because it accounts for normal differences in body fat between boys and girls and differences at various ages.

Q4: Are there limitations to BMI?
A: BMI doesn't directly measure body fat and doesn't account for muscle mass, bone density, or overall body composition.

Q5: How often should BMI be calculated for children?
A: The American Academy of Pediatrics recommends BMI calculation at least annually as part of routine health supervision.