1. What is BMI for Children?

BMI (Body Mass Index) for children and teens is age- and sex-specific and is often referred to as BMI-for-age. Unlike adults, children's BMI must be compared against growth charts to determine weight status.

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 raw BMI number must be plotted on a growth chart to determine the percentile for age and sex.

3. Importance of BMI Calculation

Details: BMI-for-age is the recommended measure for screening 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: How is children's BMI different from adults?
A: Children's BMI is interpreted relative to other children of the same age and sex using percentile charts, rather than fixed thresholds.

Q2: What do the percentile ranges mean?
A: Underweight (<5th percentile), Healthy weight (5th-85th), Overweight (85th-95th), Obese (≥95th percentile).

Q3: Where can I find NHS growth charts?
A: NHS growth charts are available from your GP or school nurse, or can be downloaded from the NHS website.

Q4: Is BMI accurate for all children?
A: BMI may not reflect body composition accurately in very muscular children or those with certain medical conditions.

Q5: How often should children's BMI be checked?
A: The NHS recommends annual BMI checks as part of the National Child Measurement Programme for children aged 4-5 and 10-11.