1. What is BMI for Children?

The Body Mass Index (BMI) is a measure that uses height and weight to work out if a child's weight is healthy. 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:

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

Explanation: The result is then compared to UK growth charts to determine the child's percentile for their age and gender.

3. Importance of BMI Calculation

Details: Tracking BMI in children helps identify potential weight problems early. The NHS uses BMI percentiles to assess whether a child is underweight, healthy weight, overweight, or obese.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What BMI percentile is considered healthy?
A: Generally, BMI between the 2nd and 91st percentiles is considered healthy for UK children.

Q2: How often should my child's BMI be checked?
A: The NHS measures BMI as part of routine child development checks at school entry (age 4-5) and in Year 6 (age 10-11).

Q3: What if my child is above the healthy weight range?
A: Consult your GP or school nurse for advice. They may suggest lifestyle changes to help your child grow into a healthy weight.

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

Q5: Where can I find official NHS growth charts?
A: NHS growth charts are available on the NHS website or through your GP/school nurse.