1. What is BMI for Children?

BMI (Body Mass Index) for children is calculated the same way as for adults, but the interpretation uses age- and sex-specific percentiles rather than fixed categories. This accounts for normal growth patterns in children.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: The result is compared to Australian growth charts to determine the percentile ranking for children of the same age and sex.

3. Understanding Percentiles

Details: Percentiles show how a child's BMI compares to others of the same age and sex. For example, 85th percentile means the child's BMI is higher than 85% of peers.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For accurate results, measure height without shoes and weight with minimal clothing.

5. Frequently Asked Questions (FAQ)

Q1: Why use percentiles instead of fixed BMI categories?
A: Children's body composition changes with growth, so percentiles account for normal developmental changes.

Q2: What are the percentile cutoffs?
A: Generally: <5th (underweight), 5th-85th (healthy), 85th-95th (overweight), ≥95th (obese).

Q3: How often should BMI be checked in children?
A: Annual checks are recommended as part of routine health assessments.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass. Athletic children may have high BMI without excess fat.

Q5: Where can I find detailed growth charts?
A: The Australian Government Department of Health provides complete growth charts for healthcare professionals.