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:

• \( weight \) — Weight in pounds (lb)
• \( height \) — Height in inches (in)
• 703 — Conversion factor (kg/m² to lb/in²)

Explanation: The equation provides a simple method to screen for weight categories that may lead to health problems.

3. Importance of BMI Calculation

Details: BMI is a reliable indicator of body fatness for most children and teens. It is used to screen for weight categories that may lead to health problems.

4. Using the Calculator

Tips: Enter weight in pounds and height in inches. All values must be valid (weight > 0, height > 0). This calculator is specifically for boys aged 2-20 years.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children?
A: For children and teens, BMI is age- and sex-specific because their body composition varies as they age and varies between boys and girls.

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

Q3: When should BMI be measured?
A: BMI should be checked at least once a year as part of routine health care for children and adolescents.

Q4: Are there limitations to BMI?
A: BMI doesn't directly measure body fat and can be influenced by factors like muscle mass. It's a screening tool, not a diagnostic tool.

Q5: Where can I find growth charts?
A: CDC growth charts are available online to plot your child's BMI-for-age percentile.