1. What is BMI for Children?

Body Mass Index (BMI) is a measure that adjusts weight for height. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age. In Australia, growth charts are used to compare a child's BMI with other children of the same age and sex.

2. How is BMI Calculated?

The calculator uses the standard BMI formula:

Where:

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

Explanation: The formula calculates body mass per unit of height squared, providing a standardized measure for comparing individuals of different heights.

3. Understanding Percentiles

Details: Australian children's BMI is compared to growth charts:

• Below 5th percentile: Underweight
• 5th to 84th percentile: Healthy weight
• 85th to 94th percentile: Overweight
• 95th percentile and above: Obese

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For accuracy, measure height without shoes and weight with minimal clothing. This calculator is intended for children aged 2-18 years.

5. Frequently Asked Questions (FAQ)

Q1: Why use BMI for children instead of adults?
A: Children's body composition varies with age and sex, so BMI must be interpreted relative to other children of the same age and sex.

Q2: How often should my child's BMI be checked?
A: Annual checks are typically sufficient unless recommended otherwise by your healthcare provider.

Q3: What if my child is very muscular?
A: BMI may overestimate body fat in muscular children. Additional assessments may be needed.

Q4: Where can I find Australian growth charts?
A: The Australian Government Department of Health provides growth charts based on WHO standards.

Q5: Should I be worried if my child is in a high percentile?
A: Consult with a healthcare professional who can consider other factors like growth patterns and family history.