1. What is BMI for Children?

Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to children and adults. For children, 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 to CDC growth charts to determine the child's percentile for their 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 can help identify potential weight problems that may lead to health issues.

4. Using the Calculator

Tips: Enter weight in kg, height in meters, age in years (2-20), and select gender. For accurate results, measurements should be taken with minimal clothing.

5. Frequently Asked Questions (FAQ)

Q1: What do the CDC BMI percentiles mean?
A: Below 5th percentile = underweight; 5th to 85th = healthy weight; 85th to 95th = overweight; 95th and above = obese.

Q2: Why use age-specific BMI for children?
A: Children's body composition changes as they grow, so BMI must be interpreted relative to other children of the same age and sex.

Q3: How often should children's BMI be checked?
A: The AAP recommends BMI screening at least annually for all children 2 years and older.

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

Q5: What if my child is below 2 years old?
A: For children under 2, weight-for-length percentiles should be used instead of BMI.