Concepts · Two-minute read
How to Read a Percentile Chart For sports parents
A percentile answers one question: out of the kids measured in the reference population, what share were at or below this value? A 10-year-old girl measuring 4 ft 6.4 in sits at the 50th percentile — half the measured population was at or below that height. It's a location in a distribution. It is not a grade, a target, or a prediction.
The typical band is wide — on purpose
At age 10, girls in the reference population span about 4 ft 2.2 in at the 5th percentile to 4 ft 10.9 in at the 95th — roughly 9 inches between kids the same age, all inside the band that is generally considered typical. Kids the same age can simply be at different points in their development. If a wide range surprises you, that's the chart doing its job.
Reading the chart: the light band spans the 5th–95th percentiles of the reference population, the darker band the middle half (25th–75th), and the line is the median. Heights in inches. Source: CDC Growth Charts (2000), National Center for Health Statistics.
The curve beats the number
One measurement is a dot. Measurements repeated over months draw a curve — and consistent growth along the same curve matters most. That's how pediatricians read these charts: not "what is the number today," but "is the pattern steady." The same logic applies to everything you measure in sport, which is exactly why My Athlete is built around the repeated record rather than one-off results.
Three things a percentile is not
- Not a grade. The 40th percentile isn't a C. It's a location among measured kids.
- Not a prediction. Today's location doesn't fix tomorrow's.
- Not a comparison to teammates. It's a national reference population, not the kids at practice.
Common questions
Is a higher percentile better?
No. A percentile describes where a measurement falls within a reference population — it is a location, not a grade. For height especially, there is no "better"; kids are measured across the whole range at every age.
What if my child's percentile changes between measurements?
Single measurements bounce around — technique, time of day, and simple variation all move the number. The pattern across many measurements is the meaningful part, and questions about that pattern belong with your pediatrician.
Do percentiles predict adult height?
A percentile describes today’s measurement against the reference population. It is not a prediction, and this page makes none. What a family can do is keep a consistent record — the pattern over the years is what any professional will want to see.
Where these numbers come from
Every value on this page is computed by My Athlete from the CDC Growth Charts (2000), published by the National Center for Health Statistics and in the public domain. We use the charts' own published LMS (Lambda-Mu-Sigma) parameters and method — no estimates, no blended sources, nothing invented. The reference population is the U.S. reference population underlying the CDC Growth Charts (2000); it describes measured distributions, not targets. How we build these tables →
Source: CDC Growth Charts (2000), National Center for Health Statistics — cdc.gov/growthcharts. Data coverage: ages 2–20. Use of these data does not imply endorsement by CDC, NCHS, HHS, or the U.S. government. · Page last reviewed: August 26, 2026
One number tells you where they are today.
The part that actually matters is the same measurement, repeated over a season — the record of measured change over time. That's what My Athlete keeps, across 18 sports, alongside every assessment your athlete does.