If you start growing hair on your chin, does it mean your growth in height has stopped? Can you do nothing to make yourself taller after you grow hair on your chin? Or is there a chance that you still can grow?
As you grow from a child into an adult, various features about your body changes in a fairly predictable pattern. Every single person doesn't always follow exactly the same pattern, but generally events occur in a similar order. One doctor by the name of Tanner became famous for writing down a general sequence and showing that most people follow it in their growth. Click here to see one such list of development events and their order.
The growth of hair above the lips and on the chin usually occurs in the middle of what Dr. Tanner called stage 4. By this time most boys have had their major growth spurt and their bodies are beginning to slow down. The bulk of height contributed by their legs have been reached. Their trunks (between the shoulder and the hips) may continue to grow at a slower rate, adding a inch or two to their height. Most of the growth in late stage 4 is focused on the broadening of the shoulders and the growth of muscle mass. To estimate what stage of development you are in, see the Tanner Stage Calculator for Boys.
Is it possible for a boy to start seeing facial hair before his growth spurt? The answer is "yes." That is why doctors look at a set of changes to decide in what stage of development a particular boy is. Generally, though, once you see chest hair (if you are of a nationality that develops chest hair), you can be fairly certain that you are within an inch of your final height. Indications that you are near the end of growth are the typical male's broad shoulders, muscular muscles, pubic hair that covers from inside thigh to inside thigh, fully developed aorta, facial hair, and chest hair.
Once you near the end of your growth, the sections of your bones which generate the most growth (called the growth plates), begin to close. Once this happens, nothing can restart them. You will see fraudulent companies selling humane growth hormones to supposedly promote further growth. Even if they are actually selling the real thing (and many are not because they are very expensive), it won't do you any good. The growth hormones have to be given while the growth plates are open. A doctor might give them to a very short child in hopes of adding an inch or two to his final height once he gets through adolescence, but they won't bother with a teenager or adult because it won't make a difference in the outcome (other than lightening your wallet).
There is a good article by Dr. Robert H. Shmerling called "Can We Predict Height?" explains many of the factors which play into a person's adult height.