1. What is BMI for Children?

BMI-for-age is a measure used to assess whether a child is underweight, normal weight, overweight, or obese. For children and teens, 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 must be plotted on UK growth charts specific to the child's age and sex for proper interpretation.

3. Importance of BMI Calculation

Details: Tracking BMI-for-age helps identify potential weight problems in children. However, it's just one tool among many for assessing a child's growth and health.

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 by a healthcare professional.

5. Frequently Asked Questions (FAQ)

Q1: What is a healthy BMI for children?
A: Unlike adults, children's BMI is assessed using percentile charts. Generally:

• Below 2nd percentile: Underweight
• 2nd to 91st percentile: Healthy weight
• 91st to 98th percentile: Overweight
• Above 98th percentile: Obese

Q2: How often should my child's BMI be checked?
A: The UK NHS recommends BMI checks at age 4-5 (reception year) and age 10-11 (year 6) as part of the National Child Measurement Programme.

Q3: Are there limitations to BMI for children?
A: Yes. BMI doesn't distinguish between fat and muscle mass. Athletic children may have high BMI due to muscle rather than fat.

Q4: Where can I find UK BMI growth charts?
A: The UK-WHO growth charts are available from the Royal College of Paediatrics and Child Health website.

Q5: Should I be worried if my child's BMI is high?
A: Consult your GP or health visitor for proper assessment. They'll consider other factors like growth pattern, diet, and physical activity.