Average Height by Age (0–20): The Complete Chart
The average height for every age from birth to 20, for boys and girls — plus the growth milestones that explain the numbers.
A 10-year-old averages about 140 cm whether boy or girl; by 18, the averages are roughly 179 cm for young men and 166 cm for young women. Girls briefly outgrow boys around ages 11–12, then boys pull ahead during their later puberty spurt.
If you are checking whether your child is "normal for their age," this chart is your starting point. The values below are rounded 50th-percentile reference figures drawn from the CDC 2000 growth charts (ages 2–20) and WHO child growth standards (under 2) — the same references pediatricians use.
One important note before the numbers: average is not the same as ideal. Healthy children spread widely around these values, and a single measurement matters far less than the pattern over time.
The complete chart: average height by age
Find the age, read across. Values are approximate 50th-percentile references in centimeters.
| Age | Boys (cm) | Girls (cm) |
|---|---|---|
| Birth | 50 | 49 |
| 1 year | 76 | 75 |
| 2 years | 88 | 87 |
| 3 years | 96 | 95 |
| 4 years | 103 | 102 |
| 5 years | 110 | 109 |
| 6 years | 116 | 115 |
| 7 years | 122 | 121 |
| 8 years | 128 | 128 |
| 9 years | 134 | 134 |
| 10 years | 140 | 140 |
| 11 years | 145 | 146 |
| 12 years | 151 | 152 |
| 13 years | 158 | 158 |
| 14 years | 166 | 162 |
| 15 years | 172 | 164 |
| 16 years | 176 | 165 |
| 17 years | 178 | 166 |
| 18 years | 179 | 166 |
| 19 years | 179 | 166 |
| 20 years | 179 | 166 |
Rounded 50th-percentile reference values based on CDC 2000 growth charts (ages 2–20) and WHO child growth standards (under 2). Individual healthy children vary widely around these figures.
Key growth milestones the chart reveals
The raw numbers hide a few patterns worth knowing:
- • The fastest growth happens in the first year: babies gain roughly 25 cm, more than in any later year of life.
- • Girls hit their puberty spurt first — which is why they are slightly taller than boys around ages 11–12.
- • Boys start their spurt about two years later but grow for longer, which is why the male average ends up about 13 cm higher.
- • Growth plates typically close around 15–17 for girls and 17–19 for boys; after that, meaningful height gain stops.
- • Between ages 8 and 10, boys and girls are nearly identical in average height — sex differences before puberty are tiny.
How to read these numbers
The chart shows the middle of the pack — half of children are above, half below. Being at the 25th or 75th percentile is just as normal as being at the 50th, as long as the child has always tracked near that line.
What actually matters to pediatricians is not any single number on this chart, but the child’s own curve: a stable percentile over the years means healthy growth, even if that percentile is the 10th or the 90th.
To see exactly where a child sits on the official curves, use the percentile calculators:
When the numbers deserve a second look
Don’t worry about one measurement. Do pay attention to the pattern:
- • The percentile drops steadily across checkups (for example, 60th → 40th → 25th)
- • Growth seems to stall for many months outside the normal slow periods
- • The child sits below the 3rd or above the 97th percentile without medical follow-up
Frequently asked questions
Is 5'8" (173 cm) tall for a 13-year-old?
Yes — well above average. A 13-year-old boy averages about 158 cm, so 173 cm lands roughly around the 90th percentile or higher. For a 13-year-old girl (average also ~158 cm at that age), it is equally above average. Keep in mind that early bloomers can be tall at 13 and end up average as adults once peers catch up.
Why are boys taller than girls after puberty?
Testosterone drives a later, longer growth spurt in boys: it starts about two years after the girls’ spurt and continues for longer, and boys’ growth plates close later (around 17–19 vs 15–17 for girls). Before puberty, the sexes are nearly identical in average height.
My child is below the average — should I worry?
Not from a single measurement. Check the percentile and, more importantly, whether it has been stable over time — a child who has always tracked near the 15th percentile is growing normally. See a pediatrician if the percentile keeps dropping, growth stalls for many months, or you are simply concerned.
At what age do teenagers stop growing?
Most girls finish growing around 15–16, roughly two years after their first period. Most boys finish around 17–18, with small gains sometimes continuing into the early 20s. Once the growth plates close, no exercise or supplement can add meaningful height.