1. What is BMI-for-age?

BMI-for-age is a measure that takes into account a child's age and sex when assessing their Body Mass Index. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age. The CDC provides growth charts to interpret BMI values for children aged 2-19 years.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in meters

Note: For children, the calculated BMI must be plotted on a CDC growth chart to determine the corresponding percentile for age and sex.

3. Importance of BMI Calculation for Children

Details: BMI-for-age is the recommended measure for screening overweight and obesity in children and teens. It helps identify potential weight problems that may lead to health issues.

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?
A: Children's body composition varies as they grow, and differs between boys and girls. BMI-for-age accounts for these differences.

Q2: What do the BMI percentiles mean?
A: Underweight (<5th percentile), Healthy weight (5th to <85th), Overweight (85th to <95th), Obese (≥95th percentile).

Q3: How often should children's BMI be checked?
A: The AAP 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 children may 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/