1. What is BMI for Boys?

BMI-for-age is the measure used to assess weight status in children and teens aged 2-20 years. For children, 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:

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

Note: For boys aged 2-20, this raw BMI value must then be plotted on CDC growth charts to determine the percentile.

3. Importance of BMI Calculation

Details: BMI-for-age is the most common indicator used to screen for weight problems in children. It's a reliable indicator of body fatness for most children and teens.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What do BMI percentiles mean?
A: Underweight (<5th percentile), Healthy weight (5th-85th percentile), Overweight (85th-95th percentile), Obese (≥95th percentile).

Q2: Why use BMI-for-age instead of regular BMI?
A: Children's body fatness changes with age and differs between boys and girls, so BMI-for-age accounts for these differences.

Q3: How often should BMI be measured in children?
A: The AAP recommends BMI screening at least annually for all children and adolescents.

Q4: Are there limitations to BMI-for-age?
A: BMI doesn't directly measure body fat and may misclassify muscular children. It also doesn't account for differences in body composition.

Q5: Where can I plot the BMI percentile?
A: The CDC provides growth charts at https://www.cdc.gov/growthcharts/clinical_charts.htm