1. What is BMI-for-age?

BMI-for-age is a measure that compares a child's weight and height to age- and sex-specific growth charts. For children and teens, BMI is age- and sex-specific because their body composition varies as they age and differs between boys and girls.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula adjusted for age and gender:

The result is then compared to CDC growth charts to determine the percentile ranking based on the child's age and gender.

3. Importance of BMI Calculation

Details: BMI-for-age is the most widely used screening tool to identify potential weight problems in children. It helps healthcare providers track growth patterns over time and identify potential health risks.

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

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

Q3: When should BMI be measured in children?
A: The American Academy of Pediatrics recommends BMI screening annually for all children aged 2 years and older.

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

Q5: What should I do if my child is in an unhealthy category?
A: Consult with a pediatrician who can perform further assessments and provide guidance on nutrition and activity.