1. What is BMI?

BMI (Body Mass Index) is a measure that uses height and weight to estimate body fat. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age.

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 against Australian growth charts to determine the percentile for the child's age and gender.

3. Importance of BMI for Australian Kids

Details: Tracking BMI-for-age helps identify children who are underweight, overweight, or at risk of becoming overweight. Early identification allows for timely intervention.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, age in years (2-18), and select gender. For accurate results, measure height and weight without shoes and heavy clothing.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children than adults?
A: Children's body composition varies as they grow, so BMI must be interpreted relative to other children of the same age and sex.

Q2: What are the BMI percentile categories?
A: Below 5th (underweight), 5th-85th (healthy weight), 85th-95th (overweight), and above 95th (obese).

Q3: How often should my child's BMI be checked?
A: Annual checks are recommended, or more frequently if there are concerns about growth or weight.

Q4: Does BMI diagnose obesity?
A: BMI is a screening tool, not a diagnostic. A healthcare provider should evaluate children with high BMI percentiles.

Q5: Where can I find Australian growth charts?
A: The Australian Government Department of Health provides growth charts based on WHO standards.