1. What is Children's BMI?

BMI (Body Mass Index) for children is calculated the same way as for adults, but interpreted differently using age and gender-specific percentile charts. The NHS uses these percentiles to assess healthy growth patterns in children aged 2-18.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Child's weight in kilograms
• \( height \) — Child's height in meters

Important: Unlike adult BMI, children's results must be compared to percentile charts that account for age and gender.

3. Importance of BMI for Children

Details: Regular BMI monitoring helps identify potential weight problems early. The NHS uses BMI percentiles to classify children as underweight, healthy weight, overweight, or obese.

4. Using the Calculator

Tips:

• Measure height without shoes
• Use current weight in light clothing
• Enter the child's exact age in years
• For most accurate results, measure at the same time of day

5. Frequently Asked Questions (FAQ)

Q1: Why are percentiles needed for children?
A: Children's body composition changes with growth, so BMI must be interpreted relative to other children of the same age and gender.

Q2: What do the percentile ranges mean?
A: Below 2nd = underweight; 2nd-90th = healthy weight; 91st-97th = overweight; 98th+ = obese (NHS classifications).

Q3: How often should children's BMI be checked?
A: The NHS recommends annual checks as part of routine growth monitoring.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between muscle and fat, so athletic children may appear overweight. Professional assessment may be needed.

Q5: Where can I find NHS percentile charts?
A: NHS growth charts are available at RCPCH website or through your GP.