1. What is BMI for Children and Teens?

BMI (Body Mass Index) is a screening tool for overweight and obesity in children and teens. For children and teens, BMI 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.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Note: The result should be interpreted using age- and sex-specific growth charts rather than adult BMI categories.

3. Importance of BMI Calculation

Details: BMI-for-age is the recommended measure for screening overweight and obesity in children and teens because it accounts for normal differences in body fat between boys and girls and differences in body fat at various ages.

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 than adults?
A: Because children's body composition varies by age and sex, BMI-for-age growth charts account for these normal developmental differences.

Q2: What BMI percentile indicates overweight or obesity?
A: Typically, ≥85th percentile is overweight, ≥95th percentile is obese. However, consult a healthcare provider for exact interpretation.

Q3: When should BMI be measured in children?
A: The American Academy of Pediatrics recommends BMI screening annually from age 2.

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

Q5: Where can I find BMI-for-age growth charts?
A: The CDC provides standardized growth charts for clinical use (https://www.cdc.gov/growthcharts/).