It’s completely normal to wonder whether your child is growing “too fast,” “too slow,” or simply differently than their peers. Growth can feel mysterious and then you add in percentiles, charts, and check-ups! But with some simple guidance, you can learn to understand your child’s growth in a way that feels grounding rather than stressful.
This post will walk you through reading growth charts, how to interpret your child’s curve, and how to advocate for your child during medical appointments. My hope is that you leave feeling informed, confident, and reassured when it comes to growth chart interpretation.
What are Growth Charts?
Growth charts help pediatricians track a child’s height and weight over time compared to a large population of children the same age and sex. Growth charts for kids are an important tool, but not a perfect one. The data used for the CDC growth charts that were revised in 2000, were created with data of American children gathered in 1964-1994.
The CDC says that, “Survey-specific sample weights were applied to the national survey sample data to assure representation of the U.S. population according to age, sex, and racial/ethnic composition at the time the surveys were conducted.” However, the US population has certainly changed a lot since that time.
When a child’s weight or height is plotted on their growth chart, it is plotted for the age that the measurement was taken. For example, for an 8 year old child that is 48 inches, a point is plotted that corresponds to 48 inches and 8 years. This plot point will represent a percentile, in this case, the 17th percentile.
What is a Percentile on a Child’s Growth Chart?
A percentile tells us how that child’s measurement compares to the population. If a child is at the 17th percentile, height-for-age, then 17 percent of individuals 8 years old are shorter than that child and 83% of 8 years old are taller than that child (based on the data used to create the growth charts.)
It’s important to remember: the goal is not to be in the 50th percentile. Every child has their own natural curve, just like they have their own eye color or temperament.
What Can Growth Charts Tell You? (and What Can’t They Tell You.)
Growth charts can:
- Show your child’s individual pattern of growth
- Help identify meaningful changes over time
- Offer a picture of your child’s body within the wider range of body diversity
Growth charts can’t:
- Tell you if your child is “healthy” based only on a percentile
- Determine the “right” size for your child
- Evaluate your child’s food intake or activity level
Understanding Your Child’s Growth Pattern
When you look at a growth chart, each plotted point represents a height or weight measurement from a specific date. These plot points, when connected by a line, represent the individual child’s “growth curve.” What matters most is the pattern over time, not any single plot point.
A few helpful things to keep in mind about growth chart interpretation:
- Height and weight are tracked separately: Children rarely grow in perfect proportion. It’s normal for weight to climb before height catches up or vice versa.
- Birth weight doesn’t predict future growth: Many children shift percentiles in the first two years of life before they settle in on “their growth pattern”.
- Breastfed and bottle-fed babies may grow differently: Both are normal. Growth patterns often stabilize by age two.
- Crossing percentiles isn’t always a problem: If a child’s weight-for-age or height-for-age curve crossed percentile lines on the CDC growth charts, it’s important to investigate. However, illness, growth spurts, puberty, or changes in nutrition or activity can all cause percentile shifts. The key is being curious why a change happened.
- BMI curves are limited: The BMI growth curve is especially unreliable. It’s volatile and skewed for taller kids. For most families, focusing on height and weight curves separately is far more helpful.
- Body diversity is real (and beautiful!): Kids (and adults!) come in all shapes and sizes. Growth charts simply compare one individual to a large population, not to an ideal.
Approaching Growth with Curiosity, Not Control
Growth is an unfolding process, not something for parents to “fix.” When you look at your child’s chart:
- Note weight and height should always be increasing during childhood. A drop in weight or flattening of the height-for-age curve should be investigated.
- Notice patterns over time. Does their growth follow along a certain percentile?
- Ask questions if something seems different. Stay curious rather than judgmental
If anything concerns you, reach out to your pediatrician, not to ask how to change your child’s body, but to understand what might be happening developmentally or medically.
Talking to Your Child’s Pediatrician
Growth conversations can feel confusing and uncomfortable, especially if you worry about how they may impact your child. Research shows that conversations about weight in front of kids can be confusing or even harmful.
We have a few resources to support you in these conversations:
The Bottom Line
Your child’s growth is a reflection of their unique body, genetics, and developmental path, not a grade or a judgment. When you take your child to their well child visit, it can feel like a test, but it is not! With a little knowledge and the right tools, you can better understand their growth curve, ask thoughtful questions, and advocate confidently.
If you’d like help interpreting your child’s growth, or you’re feeling unsure after reviewing their chart, don’t hesitate to connect with your pediatrician or a trusted nutrition professional
We’re Elizabeth & Anna!
It’s great to have you here. We’re registered dietitians and we share tips to support you in raising kids with a healthy relationship with food.
