1. What is BMI?

Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to both adult men and women. 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 (kg)
• \( height \) — Height in meters (m)

Note: For children and teens, BMI is interpreted relative to age and sex because their body composition varies as they age and varies between boys and girls.

3. Importance of BMI Calculation for Children

Details: BMI-for-age is the recommended measure for children and teens because it takes into account normal differences in body fat between boys and girls and differences in body fat at various ages.

4. Using the Calculator

Tips: Enter weight in kilograms, height in centimeters, age in years (2-20), and select gender. All values must be valid (weight > 0, height > 0, age between 2-20).

5. Frequently Asked Questions (FAQ)

Q1: Why is BMI different for children than adults?
A: Children's body composition changes as they grow, and differs between boys and girls. BMI-for-age accounts for these differences.

Q2: What is a healthy BMI for a child?
A: Healthy BMI ranges vary by age and sex. Healthcare providers use growth charts to interpret BMI-for-age.

Q3: How accurate is BMI for children?
A: BMI is a screening tool but not a diagnostic measure. It should be followed up with more direct measures of body fatness when needed.

Q4: How often should a child's BMI be checked?
A: The American Academy of Pediatrics recommends BMI calculation at least annually for all children and adolescents.

Q5: What if my child's BMI is high?
A: Consult with a healthcare provider who can perform further assessments to determine if excess fat is a problem.