1. What is BMI-for-age?

BMI-for-age is the measure used to assess weight status in children and teens (ages 2-19). Unlike adults, children's BMI must be interpreted relative to other children of the same age and sex because their body composition varies as they grow.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

For children, this value must then be plotted on CDC growth charts to determine the BMI percentile.

3. Importance of BMI Calculation for Children

Details: Tracking BMI-for-age helps identify children who are underweight, healthy weight, overweight, or obese. Early identification allows for timely intervention and healthy lifestyle promotion.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, age in years (2-19), and select gender. For accurate results, measurements should be taken with minimal clothing and no shoes.

5. Frequently Asked Questions (FAQ)

Q1: Why use BMI-for-age instead of regular BMI categories?
A: Children's body fat changes with age and differs between boys and girls. BMI-for-age accounts for these normal growth patterns.

Q2: What are the BMI percentile categories for children?
A: Underweight (<5th), Healthy weight (5th-85th), Overweight (85th-95th), Obese (≥95th).

Q3: How often should children's BMI be checked?
A: The AAP recommends annual BMI screening for all children ages 2+.

Q4: Are there limitations to BMI-for-age?
A: It doesn't distinguish between fat and muscle mass. Very muscular children may have high BMI without excess fat.

Q5: Where can I plot the BMI percentile?
A: CDC provides growth charts online or your pediatrician can help interpret the results.