How to Tell if Your Growth Plates Are Closed

The only reliable way to tell if your growth plates are closed is an X-ray read by a doctor, usually a bone-age X-ray of the left hand and wrist. Open growth plates show up as dark lines near the ends of the bones; closed ones have disappeared into solid bone. At home you can only collect hints, like no change in height over 6 to 12 months of careful measuring and being well past the end of puberty.

Can you tell if your growth plates are closed without an X-ray?

Not with certainty. Growth plates sit inside your bones near the joints, so you can't see or feel them. There is no stretch, pinch test or "knuckle check" that shows whether they are open.

What you can do is look at the clues that usually go along with the end of growth. Each one is a hint, not proof, and late bloomers can break every rule on this list.

Signs your growth plates may be closed

A few of these signs need context:

• Girls: most grow only about 1 to 2 more inches after their first period and reach adult height around 14 or 15. If your periods started two or more years ago, little growth is usually left.
• Boys: facial hair tends to come later in puberty than pubic and underarm hair. Most boys have stopped or nearly stopped growing by about 16, but a boy who started puberty late may still be growing at 17 or 18. Our guide on when boys stop growing explains the timeline.
• Shoe size: in one study of Dutch children, shoe size peaked well before the spine's growth spurt and leveled off around the time that spurt was at its fastest. So a stable shoe size can mean you are in the middle of your growth spurt, not at the end.

How to measure your height accurately at home

Because "my height stopped changing" is the most useful home clue, measure carefully:

1. Stand barefoot on a hard floor with your heels, back and head against a wall.
2. Look straight ahead and have someone place a flat book on top of your head, level with the floor.
3. Mark the wall under the book and measure from the floor to the mark.
4. Measure at the same time of day every time. People are shorter later in the day: in one small study, children lost about half an inch (1.4 cm) between morning and mid-afternoon.
5. Repeat every 3 months and write it down.

If your height is the same, within measuring error, over a full year, you are most likely at or near your adult height. The Am I Done Growing? quiz combines these clues into one estimate.

Growth plates open vs. closed on an X-ray

On an X-ray, bone looks white and cartilage looks darker because it holds less mineral. That makes growth plates easy for a doctor to spot:

• Open: a clear dark band between the end of the bone and its shaft
• Closing: the band gets thinner
• Closed: the band is gone, and the end and shaft look like one continuous bone

What is a bone-age X-ray?

A bone-age X-ray (also called a bone-age study) is a single X-ray of the left hand, wrist and fingers. You sit with your hand flat on a table, fingers spread, and stay still for 2 to 3 seconds. It is painless and uses a small amount of radiation.

A doctor compares the image with a standard reference atlas, most often the Greulich and Pyle atlas, and picks the images that match best. The result is your "bone age" in years:

• Bone age close to your real age: you are maturing on an average schedule.
• Bone age younger than your real age: your bones are behind, so you likely have more growing time left. This is common in late bloomers.
• Bone age older than your real age: you are maturing early, and growth may finish sooner.

Healthy teens can have a bone age a little different from their real age. Doctors can also combine bone age with your current height to predict adult height.

How much does a bone-age X-ray cost?

The price depends on where you live, the clinic and your insurance, so there is no single answer. It is usually ordered by a pediatrician or pediatric endocrinologist when there is a medical question about growth. Ask the imaging center and your insurer what you would pay before the appointment.

What to ask your doctor

If you are worried about your growth, these questions get useful answers:

• Is my growth rate normal for my age and stage of puberty?
• Should we plot my past heights on a growth chart?
• Would a bone-age X-ray help in my case? What is my bone age compared with my real age?
• How much growth do you expect I have left?
• Is my predicted height in line with my parents' heights?
• Do I need any blood tests, or just a recheck in 6 months?

Bring any past height measurements you have. The trend over time tells a doctor more than one number.

When to see a doctor

Ask for a checkup if:

• Your growth slowed down or stopped much earlier than friends of the same age
• You have dropped across percentile lines on your growth chart (you can check yours with the height percentile calculator)
• A boy shows no signs of puberty by about 14, or a girl by about 13
• Your growth seems far off from what your parents' heights suggest

The takeaway

You can't confirm closed growth plates at home, but steady measurements and your stage of puberty give a good hint. If your height has been flat for a year and puberty is complete, you are probably done. If you are unsure, a bone-age X-ray answers the question. While your plates are still open, our height calculator can estimate how much taller you are likely to get.