1. What is BMI-for-age?

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 is often referred to as BMI-for-age. The CDC growth charts are used to determine the corresponding BMI-for-age percentile.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: For children and teens, the BMI number is plotted on the CDC BMI-for-age growth charts to determine the percentile.

3. Importance of BMI Percentile

Details: BMI-for-age percentile shows how a child's measurements compare with others the same sex and age. This helps identify potential weight problems that may lead to health issues.

4. Using the Calculator

Tips: Enter weight in kg, 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 use BMI-for-age for children?
A: Because children's body composition varies as they grow, BMI-for-age accounts for normal differences in body fat between boys and girls and at different ages.

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 American Academy of Pediatrics recommends BMI screening annually for all children and adolescents.

Q4: Are there limitations to BMI-for-age?
A: BMI doesn't directly measure body fat and can be misleading for very muscular children or those with certain medical conditions.

Q5: Where can I find the CDC growth charts?
A: The CDC growth charts are available on the CDC website for clinical reference.