1. What is BMI for Children?

BMI-for-age is the measure used to assess weight in relation to height and age for children and teens. It is age- and sex-specific and often referred to as BMI-for-age. Percentiles are used to interpret BMI for children and teens because their body composition varies as they grow.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula adjusted for age and gender:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in meters
• Age — Between 2-20 years
• Gender — Biological sex for percentile calculation

Explanation: The result is compared to CDC growth charts to determine the BMI percentile for age and sex.

3. Importance of BMI Calculation

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 (2-20), and select gender. For most accurate results, measure height and weight with calibrated equipment.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI interpreted differently for children?
A: Children's body composition varies by age and sex as they grow, so BMI must be compared against growth charts specific to their demographic.

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

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

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between muscle and fat, and may not be accurate for very muscular children or those with certain medical conditions.

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