1. What is BMI for Children?

BMI (Body Mass Index) is a measure that adjusts body weight for height. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age. Unlike adults, children's BMI must be compared against growth charts to determine their percentile.

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 value is then plotted on CDC growth charts to determine the percentile based on age and sex.

3. Importance of BMI Calculation

Details: BMI-for-age is the recommended indicator for screening overweight and obesity in children and teens. It's used to track growth patterns and identify potential weight problems.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, age in years (2-20), and select gender. For accurate results, measurements should be taken with minimal clothing and no shoes.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children than adults?
A: Children's body composition varies by age and sex, so their BMI must be compared against growth charts specific to their age and gender.

Q2: What do the percentiles mean?
A: Percentiles show how a child's BMI compares to others of the same age and sex. Below 5th is underweight, 5th-85th is healthy, 85th-95th is overweight, and above 95th is obese.

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, or if there are sudden changes in their growth pattern.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between muscle and fat, so very athletic children may have high BMI without excess fat. It's a screening tool, not a diagnostic tool.

Q5: How often should children's BMI be checked?
A: The American Academy of Pediatrics recommends BMI screening annually starting at age 2.