Growth references · CDC data
Average Height for a 8-Year-Old (Boys & Girls)
According to the CDC Growth Charts (2000), a boy exactly 8 years old at the median — the 50th percentile — measures 4 ft 2.4 in (128.1 cm), and a girl the same age measures 4 ft 2.3 in (127.8 cm). "Average" here means the median of the U.S. reference population, not a target.
Height percentiles at age 8
| Percentile | Boys | Girls |
|---|---|---|
| 5th | 3 ft 10.8 in (118.8 cm) | 3 ft 10.7 in (118.5 cm) |
| 10th | 3 ft 11.6 in (120.8 cm) | 3 ft 11.5 in (120.5 cm) |
| 25th | 4 ft 0.9 in (124.3 cm) | 4 ft 0.8 in (123.9 cm) |
| 50th | 4 ft 2.4 in (128.1 cm) | 4 ft 2.3 in (127.8 cm) |
| 75th | 4 ft 4.0 in (132.1 cm) | 4 ft 3.9 in (131.9 cm) |
| 90th | 4 ft 5.4 in (135.7 cm) | 4 ft 5.4 in (135.6 cm) |
| 95th | 4 ft 6.3 in (137.8 cm) | 4 ft 6.3 in (137.9 cm) |
Source: CDC Growth Charts (2000), National Center for Health Statistics. Values computed from the published LMS parameters; a reference population, not targets.
The middle half of boys this age measured between 4 ft 0.9 in and 4 ft 4.0 in; the middle half of girls between 4 ft 0.8 in and 4 ft 3.9 in. Anywhere from the 5th to the 95th percentile is generally considered typical — and the pattern over time matters more than any single number. New to percentiles? See how to read a percentile chart.
Where age 8 sits on the reference curves
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.
What 8 looks like on those curves
Eight sits in the long, steady middle stretch of the curves: about 2.2 inches of median change for boys this year and 2.1 for girls, with the two medians within 0.1 inches of each other. On a field you'll see far bigger differences than the medians suggest — the middle 90% of eight-year-olds spans roughly 7 inches.
How much does the reference median move in a year?
In the reference population, the median rises about 2.2 inches for boys and 2.1 inches for girls between 8 and 9 — but individual kids move through that change on very different schedules. A single measurement is a snapshot; the record of measured change over time is what actually shows how your athlete is developing.
Common questions
What height is considered tall for a 8-year-old?
In the reference population, the 90th percentile at 8 is about 4 ft 5.4 in for boys and 4 ft 5.4 in for girls — taller than roughly nine in ten kids measured at this age. Source: CDC Growth Charts (2000).
Why is the range so wide at 8?
Kids this age arrive at each height on their own schedule — the spread comes from ordinary variation in developmental timing, not from anything a parent needs to act on. Pediatricians look at the pattern across visits rather than any single number, and everything from the 5th to the 95th percentile is generally considered typical.
Is average height different for young athletes?
These are population-wide reference values, not athlete-specific ones. At 8, what you see on a field is driven mostly by coordination and developmental timing, not size — and the most useful thing a family can do is measure the same way, over time, and watch the pattern.
How do I measure accurately at home?
Shoes off, heels against the wall, a flat rigid object pressed level on the crown, and a metal tape from the floor to the mark — the full step-by-step is in our guide, How to Measure Your Child's Height Accurately at Home.
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.