1. What is BMI for Children?

BMI-for-age is the measure used for children and teens aged 2-18 years. Unlike adults, BMI interpretation for children considers age and sex because body composition varies as children grow.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Note: The result must be interpreted using age- and sex-specific growth charts.

3. Importance of BMI Calculation

Details: BMI-for-age helps identify children who are underweight, healthy weight, overweight, or obese. It's an important screening tool but not a diagnostic measure.

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 by a healthcare professional.

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children than adults?
A: Children's body composition changes with growth, so BMI must be compared against age- and sex-specific norms.

Q2: What are the BMI categories for children?
A: Percentiles are used: underweight (<5th), healthy weight (5th-84th), overweight (85th-94th), obese (≥95th).

Q3: How often should children's BMI be checked?
A: The UK NHS recommends annual checks for children aged 2-18 as part of routine health assessments.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass. Additional assessments may be needed for very athletic children.

Q5: Where can I find UK growth charts?
A: The UK-WHO growth charts are available from the Royal College of Paediatrics and Child Health website.