The average height of an adult woman in the United States is 63.5 inches, or about 5 feet 3.5 inches. That number comes from CDC measurements taken between 2021 and 2023 on women aged 20 and older. But if you’re searching this for a child or teenager, the answer depends heavily on age, since girls grow at very different rates before, during, and after puberty.
How Girls Grow Before Puberty
From toddlerhood through the start of puberty, girls grow at a fairly steady pace of about 2.4 inches per year. This is the long, gradual phase of childhood growth where height increases predictably enough that pediatricians can track it on a standard growth chart. A girl who falls on the 50th percentile at age 5 will generally stay near that percentile through the years, barring major changes in health or nutrition.
During this phase, genetics are already doing most of the work. Roughly 80 to 90 percent of a person’s eventual height is determined by their genes, with nutrition, sleep, and overall health accounting for the rest. That’s why a girl with tall parents is likely to track above average on the growth chart long before puberty begins.
The Puberty Growth Spurt
Once puberty starts, the pace picks up sharply. Girls typically see their growth rate jump to about 3.1 inches per year during this phase. The peak of the growth spurt usually happens 6 to 12 months before a girl gets her first period. That timing matters because it means the fastest growth often occurs earlier than parents expect, sometimes between ages 10 and 12.
After the first period, growth slows down significantly. Most girls gain only about 2 to 3 more inches in total height after that point. The growth plates in girls’ bones, the soft cartilage zones near the ends of long bones where new growth happens, typically close between ages 13 and 15. Once those plates harden into solid bone, no further height increase is possible.
This is why two 12-year-old girls can look dramatically different in height. One may have already had her growth spurt and be near her adult height, while the other hasn’t started puberty yet and still has years of growing ahead. Both can end up the same height as adults.
Average Height by Age
CDC growth charts give a good sense of where the 50th percentile falls at each age. These are approximate midpoints, meaning half of girls are taller and half are shorter:
- Age 5: about 3 feet 7 inches (43 inches)
- Age 8: about 4 feet 2 inches (50 inches)
- Age 10: about 4 feet 7 inches (55 inches)
- Age 12: about 5 feet 0 inches (60 inches)
- Age 14: about 5 feet 3 inches (63 inches)
- Age 16: about 5 feet 4 inches (64 inches)
Notice how the gap between ages 10 and 12 is larger than the gap between 14 and 16. That reflects the puberty growth spurt happening for most girls in the 10 to 13 range, with growth tapering off soon after.
What Affects a Girl’s Final Height
Genetics dominate. If both parents are tall, their daughter is very likely to be tall. If both are short, she’ll probably be shorter than average. A common rough estimate is to average the parents’ heights, subtract 2.5 inches (to adjust from the male average), and that gives a ballpark for a girl’s adult height. It’s imprecise, but it captures the genetic reality.
The remaining 10 to 20 percent comes from environment. Nutrition is the biggest environmental lever. Girls who are chronically undernourished during childhood or who lack adequate protein and key minerals like calcium may not reach their genetic height potential. Chronic illness during the growing years can have a similar effect. On the flip side, there’s no supplement or food that pushes height beyond what genetics allow. Products marketed to “boost” height in healthy, well-nourished children have no scientific support.
Sleep plays a role too, since growth hormone is released primarily during deep sleep. Consistently poor sleep during childhood and adolescence can interfere with normal growth patterns.
How Average Height Varies Around the World
The 5-foot-3.5-inch U.S. average is just one data point in a wide global range. The tallest women in the world live in the Netherlands, where the average adult female height is about 5 feet 7 inches. The shortest averages are found in Guatemala, where women average roughly 4 feet 11 inches. That nearly 8-inch gap between countries reflects a combination of genetic differences between populations, variations in childhood nutrition, and differences in healthcare access.
Within any country, there’s also significant variation by ethnicity and region. In the U.S., average height differs across racial and ethnic groups by an inch or two in either direction, which is why your daughter’s pediatrician tracks her growth against her own trajectory over time rather than comparing her to a single national number.
When Height Falls Outside the Normal Range
Pediatricians pay less attention to where a girl falls on the growth chart and more attention to whether she stays on a consistent curve. A girl who has always tracked along the 15th percentile is growing normally. A girl who drops from the 60th percentile to the 15th over a year or two may warrant a closer look.
Unusually short or tall stature sometimes points to a hormonal issue, a genetic condition, or a chronic disease that’s affecting growth. Early puberty (before age 8 in girls) can also affect final height, because it starts and stops the growth spurt earlier, sometimes resulting in a shorter adult height than expected. Late puberty has the opposite effect, giving bones more time to grow before the growth plates close.
If your child’s growth pattern seems unusual, a pediatrician can order a bone age X-ray, which shows how mature the growth plates are compared to the child’s actual age. This gives a much better prediction of remaining growth potential than height alone.