Growth Percentiles
Enter your child's date of birth, the date they were weighed or measured, and their weight and/or height. This tool works out exactly how old they were on that date and then shows the precise weight- and height-for-age percentile they fall in — based on official CDC growth-chart reference data for children from birth to 20 years — so you can see where your child lies rather than just reading off a chart.
How to interpret a percentile
- A percentile is a comparison, not a grade. A child at the 10th percentile for weight is not underweight, and a child at the 90th percentile is not overweight — the percentile simply shows where a child falls relative to peers of the same age and sex.
- Trend matters more than a single number. Pediatricians pay closer attention to whether a child is tracking consistently along their own growth curve over time than to any single percentile reading.
- This tool is a reference, not a diagnosis. If you have concerns about your child's growth, weight gain, or weight loss, discuss it with your pediatrician, who can plot growth against a full clinical history.
What a percentile means
A growth percentile compares your child to a large reference population of children of the same age and sex — it doesn't compare your child to some fixed ideal. A child at the 25th percentile for weight is simply lighter than about 75% of children that age and sex, and a child at the 75th percentile is heavier than about 75% of them. Being toward either end of the range is common and, on its own, is not a cause for concern.
How to interpret your child's number
There is a wide range of percentiles that count as healthy, and a single reading only captures one moment in time. What matters more to most pediatricians is how a percentile compares to that same child's own past readings — a child who has tracked steadily near the same percentile for months or years is generally following an expected, individual growth pattern, whether that pattern sits near the top, middle, or bottom of the chart.
What matters more than a single number
The trend over time carries more clinical meaning than any one percentile in isolation. A sudden jump or drop across percentile lines — sometimes called "crossing percentiles" — is generally what prompts a closer look from a pediatrician, since it can reflect a change in feeding, illness, or another factor worth discussing. If you notice a significant shift in your child's growth pattern, bring it up at the next well visit rather than waiting.
Sources & references
These references informed the guidance on this page. They are provided for transparency and further reading; they are not endorsements, and this page is not a substitute for the advice of your child's own clinician.