1. What is BMI for Children?

BMI (Body Mass Index) 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, so their BMI needs to be compared against growth charts.

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 plotted on CDC growth charts to determine the percentile for the child's age and sex.

3. Importance of BMI Calculation

Details: BMI-for-age is the recommended indicator for screening overweight and obesity in children and teens. It's a reliable indicator of body fatness for most children and teens.

4. Using the Calculator

Tips: Enter weight in kg, height in meters, age in years (2-19), 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 BMI must be compared against growth charts specific to their demographic.

Q2: What do the percentiles mean?
A: Percentiles show how a child's BMI compares to others of the same age and sex. Below 5th: underweight; 5th-85th: healthy weight; 85th-95th: overweight; 95th+: obese.

Q3: How often should children's BMI be checked?
A: The American Academy of Pediatrics recommends BMI screening at least annually for all children and adolescents.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass. Very muscular teens might have a high BMI without excess fat.

Q5: Where can I find CDC growth charts?
A: CDC growth charts are available at https://www.cdc.gov/growthcharts/clinical_charts.htm