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 BMI formula:

Where:

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

Note: For adolescents, BMI is interpreted using age- and sex-specific percentiles from CDC growth charts.

3. Importance of BMI Calculation

Details: BMI is a screening tool to identify possible weight problems in children and teens. However, it is not a diagnostic tool and should be followed up with further assessment.

4. Using the Calculator

Tips: Enter weight in kg, height in meters, age in years (2-19), and select gender. All values must be valid (weight > 0, height > 0, age between 2-19).

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children and teens?
A: Children's body composition varies as they grow, so BMI must be compared against age- and sex-specific standards.

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

Q3: When should BMI be measured?
A: BMI should be calculated at least annually for children and teens as part of routine health assessments.

Q4: Are there limitations to BMI?
A: BMI doesn't directly measure body fat and may misclassify muscular individuals. It's a screening tool, not a diagnostic.

Q5: Where can I find CDC growth charts?
A: CDC growth charts are available on the CDC website for clinical interpretation of BMI-for-age.