1. What is BMI?

Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to adults, children, and teens. 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:

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

Note: For children and teens, BMI is interpreted using age- and sex-specific percentiles rather than the adult categories.

3. Importance of BMI Calculation

Details: BMI is a screening tool to identify possible weight problems in children and teens. However, it is not a diagnostic tool and should be followed up with further assessment.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, age in years (2-19), and select gender. All values must be valid (weight > 0, height > 0, age between 2-19).

5. Frequently Asked Questions (FAQ)

Q1: What is a healthy BMI for children?
A: For children, BMI is interpreted using growth charts that show the percentile ranking based on age and sex. A BMI between the 5th and 85th percentiles is considered healthy.

Q2: Why is BMI different for children than adults?
A: Children's body composition varies as they grow, and between boys and girls. BMI-for-age accounts for these differences.

Q3: How often should children's BMI be checked?
A: The Canadian Paediatric Society recommends BMI measurement at least annually for children over 2 years of age.

Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass. Athletic children may have high BMI due to muscle rather than fat.

Q5: Where can I find Canadian BMI growth charts?
A: The World Health Organization (WHO) growth standards are used in Canada for children under 5, while the CDC growth charts are used for children 5-19.