1. What is BMI for Children?

Body Mass Index (BMI) is a measure that adjusts body weight for height. For children, BMI is age- and sex-specific and is often referred to as BMI-for-age. It's compared to growth charts to determine percentile ranking.

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 child's percentile for their age and gender.

3. Importance of BMI Calculation for Children

Details: Tracking BMI-for-age helps identify children who are underweight, at a healthy weight, overweight, or obese. Early identification allows for timely intervention.

4. Using the Calculator

Tips: Enter weight in kg, height in meters, age in years (2-18), and select gender. For accurate results, measurements should be taken with minimal clothing and no shoes.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children than adults?
A: Children's body composition varies by age and sex, so their BMI must be compared to growth charts specific to their demographic.

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

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

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between muscle and fat, so athletic children may have high BMI without excess fat.

Q5: How often should my child's BMI be checked?
A: The AAP recommends BMI screening annually starting at age 2.