Can you still grow taller after 18?

Usually not by much, but it happens. People who started puberty late can have open growth plates into their late teens or occasionally early twenties, and the spine matures slightly later than the legs. However, most height change adults notice is daily spinal compression — you are commonly around 1–2 cm taller in the morning than at night — or posture, not real growth. Once growth plates close, no product or exercise can lengthen bones.

Do girls stop growing after their first period?

Not immediately, but growth slows sharply. Girls typically hit their fastest growth early in puberty, before menstruation begins. After the first period, most girls add only a few more centimeters and finish growing within about one to two years, which is why most reach adult height around ages 14 to 16. Timing varies widely and normally from person to person.

Why am I taller in the morning than at night?

During the day, gravity gradually compresses the soft discs between the vertebrae in your spine; overnight, lying down lets them rehydrate and expand. The difference is commonly around 1–2 cm and is completely normal — it is not growth. This is why height should be measured at a consistent time of day, using the same careful technique, if you want readings you can fairly compare over time.

Growth Science

When Do You Stop Growing? Typical Age Ranges Explained

Q: When do growth plates close?

Growth plates — the cartilage layers near the ends of long bones where new bone forms — close by the end of puberty, typically in the mid-teens for girls and the late teens for boys. Closure follows skeletal maturity rather than calendar age, which is why doctors sometimes assess growth with a hand and wrist X-ray. Once a plate closes, that bone's lengthening is permanently complete and adult height is set.

The Height Almanac · Updated 2026-07-19 · 4 min read

When Do You Stop Growing? Typical Age Ranges Explained

SummaryMost people stop growing in height by the end of puberty. Girls typically finish growing around ages 14 to 16, usually within a couple of years after their first period. Boys, who start puberty later, typically finish around 16 to 18, sometimes with small gains into the late teens. Growth ends when the growth plates in the long bones close; after that, bones cannot lengthen further. Individual timing varies widely and normally.

Contents

When Do You Stop Growing? The Short Answer
How Height Growth Actually Works
Typical Ages by Sex
Do You Grow After 18?
When Do Growth Plates Close?
Tracking Growth the Right Way

When Do You Stop Growing? The Short Answer

Most people stop growing in height by the end of puberty. For girls, that typically means height growth finishes around ages 14 to 16, usually within a couple of years after their first period. For boys, who start puberty later on average, growth typically finishes around ages 16 to 18, with some continuing to add small amounts into their late teens. Growth ends when the growth plates in the long bones close — after that, bones can no longer lengthen, and adult height is set.

Those are population-level patterns, not deadlines. Individual timing varies widely and normally, and only a doctor reviewing growth over time can say anything about a specific person.

How Height Growth Actually Works

Height comes almost entirely from the lengthening of your long bones — mainly the femur and tibia in the legs and the vertebrae of the spine. Near each end of a growing long bone sits a growth plate (epiphyseal plate), a layer of cartilage where new bone tissue is continuously added during childhood and adolescence.

Growth is not steady. It follows three broad phases:

Infancy: the fastest growth of your life. Babies typically add roughly 25 cm (about 10 inches) in their first year.
Childhood: a long, steady phase, commonly around 5–6 cm (about 2–2.5 inches) per year.
Puberty: a final acceleration called the pubertal growth spurt, when annual growth can roughly double for a year or two before tapering to zero.

Hormones drive the finale. The same sex hormones that power puberty — especially estrogen, in both sexes — first accelerate growth and then mature the growth plates until they close.

Typical Ages by Sex

Because puberty starts earlier in girls, the whole timeline shifts earlier for them. The ranges below reflect broad, well-established patterns from standard pediatric references.

Milestone	Girls (typical)	Boys (typical)
Puberty begins	8–13	9–14
Peak growth spurt	~11–13	~13–15
Height growth mostly complete	~14–16	~16–18

When Do Girls Stop Growing?

Girls usually hit their fastest growth early in puberty, before their first period. After menstruation begins, growth slows sharply — most girls add only a few more centimeters, typically finishing within about one to two years. That is why most girls reach adult height around 14 to 16.

When Do Boys Stop Growing?

Boys start puberty later and hit their growth spurt later, typically peaking in the mid-teens. Growth then winds down through the late teens, with most boys reaching adult height by 16 to 18. Late bloomers exist on both sides of these ranges: a boy who starts puberty at 14 may still be gaining height at 18, and that can be completely normal.

Do You Grow After 18?

Sometimes — but usually not by much. A few honest distinctions matter here:

Some people genuinely grow past 18. If puberty started late, growth plates can remain open into the late teens or, occasionally, the early twenties. This is the exception, not the rule.
The spine matures last. Long-bone growth in the legs finishes first; the vertebrae can contribute small gains slightly later.
Daily height changes are not growth. Everyone is a bit taller in the morning than at night because the discs in the spine compress under gravity during the day and rehydrate overnight. The difference is commonly around 1–2 cm. If you have "grown" since last night, this is why — our step-by-step measuring guide explains how to control for it.
Posture changes are not growth either. Standing straighter can raise a measured reading without any bone lengthening at all.

After the growth plates close, no supplement, stretch, exercise, or gadget can lengthen bones. Anything marketed as adult "height increase" is trading on hope, not biology.

When Do Growth Plates Close?

Growth plates close in a predictable sequence as skeletal maturity advances, and the process is finished by the end of puberty — typically by the mid-teens in girls and the late teens in boys. Once a plate closes, the cartilage is replaced by solid bone and that bone's lengthening is permanently complete.

Closure tracks skeletal age, not birthday age. Two 15-year-olds can be years apart in bone maturity, which is why doctors sometimes assess growth using a hand and wrist X-ray rather than the calendar. It is also why the age ranges in this article are ranges, not cutoffs.

Tracking Growth the Right Way

If you or your child are still growing, the trend matters far more than any single number. A reading taken at night, in shoes, against a tilted head will not compare fairly with one taken carefully in the morning.

To track honestly:

Measure at a consistent time of day, ideally the same each time.
Use proper technique — heels, back, and head against the wall, eyes level. The methods in our measuring guides cover the details.
Compare across months, not days. Real growth shows up as a trend line.

A final note: everything above describes broad population patterns. Individual growth varies widely and normally. If you have concerns about growth — yours or your child's — a doctor or pediatrician can assess it properly over time, which no article can do.