1. What is BMI for Children?

BMI (Body Mass Index) for children is a measure that adjusts for age and gender, as children's body composition varies as they grow. Unlike adults, children's BMI is compared to growth charts specific to their age and sex.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Note: For children, the raw BMI number must be plotted on age- and sex-specific growth charts to determine the percentile, which indicates whether the child is underweight, normal weight, overweight, or obese.

3. Importance of BMI Calculation

Details: BMI-for-age is the recommended screening tool for overweight and obesity in children aged 2-18 years. It helps identify potential weight problems that may lead to health issues.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, age in years (2-18), and select gender. For accurate results, measurements should be taken with minimal clothing and no shoes.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children than adults?
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 BMI percentile indicates overweight?
A: Typically, ≥85th percentile is overweight and ≥95th percentile is obese, but consult local growth charts for specific cutoffs.

Q3: Are there limitations to BMI for children?
A: BMI doesn't distinguish between muscle and fat, so athletic children may have high BMI without excess fat. It's a screening tool, not a diagnostic.

Q4: How often should children's BMI be checked?
A: Annual screening is recommended for children over 2 years old as part of routine health checks.

Q5: Where can I find growth charts?
A: The UK and New Zealand use similar growth charts based on WHO standards, available through health departments or pediatric organizations.