1. What is Child BMI?

Body Mass Index (BMI) is a measure that uses height and weight to assess whether a child's weight is healthy for their height. For children, BMI is age and sex-specific and is compared to growth charts to determine percentiles.

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

3. Importance of Child BMI Calculation

Details: Tracking BMI in children helps identify potential weight problems early. The UK uses BMI centile charts to monitor growth patterns from age 2-18.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Why are child BMI percentiles different from adult categories?
A: Children's body composition changes as they grow, so BMI must be interpreted relative to other children of the same age and sex.

Q2: What do the percentiles mean?
A: Below 5th: underweight; 5th-85th: healthy weight; 85th-95th: overweight; Above 95th: obese.

Q3: When should I be concerned about my child's BMI?
A: Consult a healthcare professional if your child is below 5th or above 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 athletic children may appear overweight. It's one of several growth indicators.

Q5: Where can I find official UK growth charts?
A: The UK-WHO growth charts are available from the Royal College of Paediatrics and Child Health website.