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.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: The result is compared against CDC growth charts for boys aged 2-19 years to determine the percentile.

3. Importance of BMI Calculation

Details: BMI-for-age is the recommended indicator for screening overweight and obesity in children and teens. It's a reliable indicator of body fatness for most children.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, and age in years (2-19). For accurate results, measure height without shoes and weight with minimal clothing.

5. Frequently Asked Questions (FAQ)

Q1: Why use BMI-for-age instead of regular BMI?
A: Children's body composition varies as they grow, so BMI must be interpreted relative to other children of the same age and sex.

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

Q3: How often should children's BMI be checked?
A: The American Academy of Pediatrics recommends BMI assessment at least annually.

Q4: Are there limitations to BMI?
A: BMI doesn't directly measure body fat and may misclassify muscular children as overweight.

Q5: What if my child is above the 95th percentile?
A: Consult a healthcare provider for further evaluation and guidance.