1. What is BMI for Children?

BMI (Body Mass Index) for children is a measure that adjusts weight for height, age and sex. Unlike adults, children's BMI is interpreted using age- and sex-specific percentiles from growth charts, such as the UK-WHO growth charts.

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 value must be plotted on age- and sex-specific growth charts to determine the BMI percentile.

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 age- and sex-specific and interpreted using percentile charts rather than fixed thresholds.

Q2: What are the UK BMI percentile categories?
A: Underweight (<2nd percentile), Healthy weight (2nd-91st percentile), Overweight (91st-98th percentile), Obese (>98th percentile).

Q3: When should BMI be measured in children?
A: The UK National Childhood Measurement Programme measures children in Reception (age 4-5) and Year 6 (age 10-11).

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass. Athletic children may have high BMI without excess fat.

Q5: Where can I plot my child's BMI percentile?
A: The UK-WHO growth charts are available from the Royal College of Paediatrics and Child Health website.