1. What is BMI for Children?

BMI (Body Mass Index) for children and teens 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: For children, the BMI number is plotted on CDC growth charts to determine the BMI-for-age percentile.

3. Importance of BMI Calculation for Kids

Details: BMI-for-age is the most widely used screening tool for identifying potential weight problems in children. It helps identify children who are underweight, healthy weight, overweight, or obese.

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 different for children than adults?
A: Children's body fat changes with age and differs between boys and girls, so BMI for children is age- and sex-specific.

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

Q3: When should I be concerned about my child's BMI?
A: Consult a healthcare provider if your child is below the 5th percentile or above the 85th percentile.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass. Athletic children may have high BMI due to muscle rather than fat.

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