Taking the confusion out of reading a growth chart

Have you ever taken your child to the pediatrician and looked at the growth chart and thought, “That looks like the controls to an aircraft I don’t know how to fly”?

There’s no shortage of potentially confusing information when it comes to your child’s health. But understanding your child’s growth patterns doesn’t have to be one of the confusing parts. Asma Khan, DO, an OSF HealthCare pediatrician, breaks down how to take the confusion out of reading a growth chart.

Choosing your chart

First things first: Find the right chart. Start by checking out the Centers for Disease Control and Prevention website for a variety of growth charts.

If you live in the United States, you’ll likely be looking at charts for the 5th and 95th percentile. This chart is widely used by pediatricians.

Second, decide whether you need a chart for a boy or girl.

“Girls and boys have different growth charts because they grow in different patterns and at different rates,” Dr. Khan said.

Then, choose the chart that aligns with the age range of your child.

“In children birth to 36 months, we measure weight, height and head circumference. In children age 2 years and older, we look at height, weight and body mass index (BMI),” Dr. Khan said.

After that, choose what measurement you want to find.

Do you want to know your child’s weight and length percentiles? Choose the length-for-age and weight-for-age chart. Do you want to know your child’s percentile for head circumference? Choose the head circumference-for-age chart.

Finally, you’re left with some basic preferences. There are English, French and Spanish options. You also get to choose whether to view the chart in color or black and white.

Reading the lines

Now you’re ready to find your child’s measurements.

Download our “how to” guide.

Age is at the top and bottom of the chart, and length and weight are along the left and right sides. The curved lines show the percentile numbers, or patterns of growth.

The percentile number means that your child’s growth exceeds that percentage of other children their age. If your child is in the 75th percentile for weight, that means that your child weighs more than 75% of children the same age.

It doesn’t matter whether your child measures at a low or high percentile. It only matters that your child is following the curved lines, which indicates that your child is growing in a healthy way over time.

To find your child’s growth percentile, follow these simple steps described by Dr. Khan.

  • Step 1: Find your child’s age at the bottom of the grid. Draw a vertical line (up and down) at this point.
  • Step 2: Find your child’s weight on either the right or left side of the grid. Draw a horizontal line (side to side) at this point.
  • Step 3: Draw a dot where the two lines intersect.
  • Step 4: Find the curve that is closest to that dot. Follow the line of the curve up. Go all the way to the end. The number at the end of the curve is your child’s percentile rank for weight. Your answer will be at the end of that curve.
  • Repeat: Find your child’s length on either side of the grid. Draw a horizontal line (side to side) at this point. Find the intersection of your child’s length and age.

Knowing what’s healthy

“Being in a high or a low percentile doesn’t necessarily mean that a child is healthier or has a growth or weight problem,” Dr. Khan said.

The percentile number is not the most important thing your child’s pediatrician is looking for. They just want to know that your child is growing at a healthy rate.

“There is no ideal percentile. Healthy children come in all shapes and sizes, and a baby who is in the 5th percentile can be just as healthy as a baby who is in the 95th percentile,” Dr. Khan said.

The pediatrician is the leading source for tracking your child’s health and growth. If you have any concerns or questions about your child’s weight or height, your child’s pediatrician will have all the answers.

Last Updated: January 7, 2022

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About Author: Katie Faley

Katie Faley is a Writing Coordinator for OSF HealthCare. She graduated from Illinois State University with a degree in English Studies. Before joining OSF HealthCare in 2021, she worked in magazine editing, digital marketing and freelance writing.
Katie is often found listening to ‘60s folk music, deciding on a new skill to learn, losing track of time in a library or spending time with her family and friends.

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Categories: Kids & Family