When Do Boys Stop Growing?

If you have a tween or teen son (in this case, a child who was assigned male at birth), you may be wondering when they will stop growing and reach their full adult height. Remember, too, that growing isn't just about height. As your child grows and matures during the teen years, they will be experiencing many complex and sometimes surprising changes. As you anticipate the process and watch it unfold, you will likely have many questions.

Many parents wonder when growth in puberty begins and what to expect in terms of changes and growth spurts. Other questions include how to know if your child isn’t growing properly and when will your child will be finished growing.

Growth Timeline for Boys

All kids have their own specific timeline when it comes to growth and physical maturation, and follow their own curve. That said, girls (children assigned female at birth) usually start and end puberty earlier than boys do by 1 to 2 years. This is why many middle school girls sometimes tower over their male counterparts.

Boys usually start puberty at around 11 or 12 years old. Once puberty starts, the process usually lasts about four years, at which point most significant growth concludes. As such, most boys are done growing by the time they are about 16 years old, but some boys don’t reach their full adult height until they are 18 years old—and some even later.

When Does Puberty For Boys Start?

Whereas girls may begin puberty at 8 to 13 years old, boys generally start a year or two later, somewhere between 9 to 14 years old, with an average of 11 years old. Most boys have started the process by 14 years old, and if you don’t see signs of puberty in your child by then, you should discuss this with your doctor.

What Are the Signs of Puberty?

Puberty isn’t just about growing in height: it encompasses many important bodily changes. Some of these changes may seem strange or uncomfortable for your child to talk about. It’s good for you to have a general sense of what to expect so that you can answer any questions your child might have about what is happening in their body.

Here is the general timetable of when puberty changes happen in boys. Exactly when boys start this process varies, but once it starts, it usually follows a similar order.

Early Signs of Puberty

The first sign of puberty in boys is the enlargement of the testes as well as the darkening of the scrotum and a thinning of its skin. Another early sign is the appearance of pubic hair at the base of the penis.

Other Signs of Puberty

After about a year, more physical changes happen, usually in quick succession:

• The testicles continue to grow; the scrotum continues to darken and hang lower
• Pubic hair becomes thicker and more abundant, followed by underarm hair, facial hair, and thickening of leg and arm hair; chest hair usually appears last
• The penis will grow, first in length, and then width, with complete growth happening between 13 to 18 years old
• Boys will begin having wet dreams, or nocturnal ejaculations, during puberty. They may also begin to masturbate frequently, which is normal
• Boys’ voices will deepen as puberty progresses
• Most boys will develop pimples or acne during this time as well

Growth Spurts During Puberty

All boys are different when it comes to growth spurts, but boys most definitely have them as they are growing during puberty! In fact, puberty is the time period when at least 25% of your boys’ overall growth will happen.

The peak of boys’ growth spurts usually happen during the latter part of puberty, about two years after the onset of puberty. During this time, they may grow about 3 inches per year. Most growth will end by the time boys are 16, but they may continue to grow until they are 18.

What Impacts Your Child’s Height?

A child’s height is primarily determined by genetics, and is usually determined by a combination of the child mother’s and father’s genetic makeup.

In rare cases, your child may have imbalances with their growth hormones, which will cause them to grow abnormally quickly or slowly. In this case, a full doctor’s assessment will be necessary.

What To Do If You Are Concerned About Your Teen’s Growth

Again, there is a wide range of normal when it comes to boys’ growth during puberty. Some boys start as early as 9 years old or as late as 14 years old.

However, if your son starts showing signs of puberty before 9 or isn’t showing any signs of puberty by the time they are 14, consult their pediatrician. If your pediatrician thinks there may be issues with your child’s growth, they may suggest testing, including hormonal assessments and even x-rays to measure skeletal growth and development.

If your pediatrician recognizes that there is an issue, they may refer you to a specialist, such as pediatric geneticist or pediatric endocrinologist.

A Word From Verywell

Many parents worry about the growth that happens during puberty. Is my child growing too fast? Too slow? Do I need to alter their diet? When will they stop growing out of their clothes and eating everything in sight?

Kids who are going through puberty may feel concerns about their growth as well, especially if they compare their growth to their peers. If your child is the first or last to go through the growth spurts of puberty, they may feel self-conscious or anxious. 

As a parent, you can ensure that your child gets through the sometimes troubling journey of puberty by having open conversations with them about the changes that are happening to their bodies, and normalizing even the most awkward parts.

Be sure to remain positive about their body’s appearance as well as the pace at which they are growing. Likewise, if you have any concerns about your child’s growth or development during puberty, be sure to contact your pediatrician.