1. What is BMI?

Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to children and adults. For children and teens, 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 adjusted for children:

Where:

• \( weight \) — Weight in kilograms (converted to pounds)
• \( height \) — Height in feet (converted to inches)
• \( age \) — Age in years (2-19 for pediatric BMI)

Explanation: The result is compared against CDC growth charts to determine the percentile for the child's age and gender.

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 feet, 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 use BMI-for-age for children?
A: Because children's body composition varies as they grow, BMI must be interpreted relative to other children of the same age and sex.

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

Q3: When should BMI be measured in children?
A: The American Academy of Pediatrics recommends BMI screening annually for all children aged 2 years and older.

Q4: Are there limitations to BMI?
A: BMI doesn't directly measure body fat and may misclassify muscular children. It's a screening tool, not a diagnostic.

Q5: What should I do if my child's BMI is high?
A: Consult a healthcare provider for further evaluation. They may assess diet, physical activity, family history, and other health markers.