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, the BMI value is plotted on a growth chart to determine the corresponding BMI-for-age percentile.

3. Importance of BMI Calculation for Children

Details: BMI-for-age is the recommended indicator for screening overweight and obesity in children and teens. It accounts for 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 (0-18), and select gender. All values must be valid (weight > 0, height > 0, age between 0-18).

5. Frequently Asked Questions (FAQ)

Q1: What is a healthy BMI for children?
A: Unlike adults, BMI categories for children are age and sex specific. Percentiles are used to interpret BMI for children.

Q2: How are BMI percentiles interpreted?
A: Underweight (<5th percentile), Healthy weight (5th to <85th percentile), Overweight (85th to <95th percentile), Obese (≥95th percentile).

Q3: Why use BMI for children?
A: BMI is an inexpensive and easy-to-perform screening tool for potential weight problems in children.

Q4: Are there limitations to BMI for children?
A: BMI doesn't measure body fat directly and can be influenced by factors like muscle mass and growth spurts.

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