1. What is BMI?

Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in children. For children, 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

Note: For children, the calculated BMI should be plotted on a BMI-for-age growth chart to determine the percentile.

3. Importance of BMI Calculation for Children

Details: BMI is an important screening tool for identifying possible weight problems in children. However, it is not a diagnostic tool and should be followed up with further assessment by a healthcare provider.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For accurate results, measurements should be taken with minimal clothing and no shoes.

5. Frequently Asked Questions (FAQ)

Q1: How is child BMI different from adult BMI?
A: For children, BMI is interpreted relative to a child's age and sex because their body composition varies as they grow.

Q2: What are the BMI categories for children?
A: Children are classified as underweight (<5th percentile), healthy weight (5th to <85th), overweight (85th to <95th), or obese (≥95th percentile).

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

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

Q5: Where can I find BMI-for-age growth charts?
A: The NSW Health website and CDC provide BMI-for-age growth charts for boys and girls.