Child Growth Percentile Calculator
Enter your child’s age, sex, and a height or weight measurement to estimate their percentile on the growth curve — a quick sense check between pediatrician visits.
Estimated percentile
A rough reference against approximate growth data — not a medical diagnosis. Your pediatrician uses the official CDC/WHO charts and your child’s full history.
How the estimate works
The calculator looks up an approximate median measurement for a child of your child’s age and sex, then measures how far above or below it your figure sits using a z-score— the number of standard deviations from the middle. That z-score is converted to a percentile with the normal-distribution model that underpins growth charts.
Because it relies on compact reference values rather than the full clinical dataset, it is best used to catch large outliers and to understand what a percentile means — not to make any health decision. For that, your pediatrician’s charts and judgement are the right tools.
Frequently Asked Questions
What does a percentile actually mean?
A percentile compares your child to a large reference group of the same age and sex. The 60th percentile for height, for example, means that out of 100 children, your child would be taller than about 60 of them. Being at the 20th or the 80th is perfectly normal — it's the overall trend over time that matters most.
Is a low or high percentile something to worry about?
Usually not on its own. Children come in a wide range of healthy sizes, and a steady percentile — high or low — is generally reassuring. What pediatricians watch for is a sudden jump or drop across the curve. If you're concerned about your child's growth, that conversation belongs with their doctor.
How accurate is this tool?
It uses approximate reference medians and a statistical model to estimate a percentile, so treat the result as a rough ballpark for ages 2 to 12. The official CDC and WHO growth charts your pediatrician uses are far more precise and account for your child's full history.
Can I enter inches and pounds?
Yes. Choose your unit and the calculator converts to metric before comparing, so you can enter height in centimetres or inches and weight in kilograms or pounds.
This is a rough educational estimate, not medical advice or a diagnosis. Always rely on your pediatrician and the official growth charts for any decision about your child’s health.