1. What is BMI for Children?

BMI for children and teens is age- and sex-specific and is often referred to as BMI-for-age. Unlike adults, children's body composition varies as they age and differs between boys and girls. Therefore, BMI for children must be interpreted relative to other children of the same sex and 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 then compared to CDC growth charts to determine the weight category based on age and gender.

3. Importance of BMI Calculation

Details: BMI-for-age is the recommended measure for screening overweight and obesity in children and teens. It's a reliable indicator of body fatness for most children and teens, though it doesn't measure body fat directly.

4. Using the Calculator

Tips: Enter weight in kilograms, 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 interpreted differently for children than adults?
A: Children's body composition varies as they age and differs between boys and girls. BMI-for-age accounts for these differences.

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

Q3: When should I be concerned about my child's BMI?
A: Consult a healthcare provider if your child is below the 5th percentile or at or above the 85th percentile.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass. Athletic children may have a high BMI due to increased muscle.

Q5: How often should children's BMI be checked?
A: The American Academy of Pediatrics recommends BMI screening annually for all children ages 2 years and older.