1. What is BMI?

Body Mass Index (BMI) is a value derived from the mass and height of a person. 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 standard BMI formula:

Where:

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

For children: The interpretation of BMI is different for children and teens than for adults. BMI-for-age is plotted on growth charts to determine weight status categories.

3. Importance of BMI Calculation

Details: BMI is a simple screening tool that can indicate whether a child is underweight, healthy weight, overweight, or obese. 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. All values must be valid (weight > 0, height > 0, age between 2-18).

5. Frequently Asked Questions (FAQ)

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

Q2: What are healthy BMI ranges for children?
A: Healthy ranges vary by age and gender. Generally, BMI between the 5th and 85th percentiles is considered healthy weight.

Q3: When should I be concerned about my child's BMI?
A: If your child's BMI is below the 5th percentile or above the 85th percentile, consult a healthcare provider.

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

Q5: How often should children's BMI be checked?
A: Yearly checks are recommended as part of routine health assessments.