1. What is BMI?

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

Where:

• \( weight \) — Weight in kilograms
• \( height \) — Height in meters

Note: For children, the BMI number is plotted on growth charts to determine a percentile ranking.

3. Importance of BMI Calculation

Details: BMI is a screening tool that can indicate whether a child is underweight, healthy weight, overweight, or obese. It helps identify potential weight problems.

4. Using the Calculator

Tips: Enter weight in kg, height in meters, age in years (2-18), and select gender. For accurate results, measurements should be taken carefully.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children?
A: Children's body composition varies with age and between boys and girls, so BMI must be interpreted relative to other children of the same age and sex.

Q2: What are the BMI categories for children?
A: Underweight (<5th percentile), Healthy weight (5th-85th), Overweight (85th-95th), Obese (≥95th percentile).

Q3: When should BMI be measured in children?
A: The NHS recommends measuring BMI annually from age 2 as part of routine growth monitoring.

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

Q5: What should I do if my child's BMI is concerning?
A: Consult a healthcare provider for a full assessment - they may consider other factors like growth patterns and additional measurements.