Puberty Stages for Boys

Part of the Tanner scale (sometimes called the Tanner stages) is widely accepted as a summary of the physical and secondary sex characteristics that show up as adolescents mature. As a whole, it looks at the primary and secondary sex characteristics in children, adolescents, and adults, but it can be used to explain what to expect during puberty as well. The scale was developed by a pediatrician named James Tanner.

In Stage 1, usually around 10-years old and younger, there is no pubic hair and the testicles and penis do not enlarge. No growth spurts tend to happen, but children in this stage continue to grow about five to seven centimeters per year. This is average for children between six and twelve years old.

In Stage 2, there is still no rapid height gain, but the testicles and penis may slightly increase in size. Your penis will get longer and wider, and pubic hair will begin to grow around the base of the penis. This is around age 9.5 to 14.5. According to DrPaul.com, you may begin to enter puberty any time between ages 9 and 14. Along with the penis and testicle growth comes redness around the scrotum.

In Stage 3, height increases a bit more, at a slightly faster rate (about seven to eight centimeters per year instead of the average five to six). Your testicles and penis will continue to increase in size. The pubic hair changes in texture, becoming coarse and dark, and spreads out further along the pubic area. It doesn't make it to the thighs at this point. You may notice your voice cracking at this stage, and you'll become more muscular. This stage could happen between 10 and 16.5 years old.

With Stage 4 comes a major growth spurt. You'll grow up to ten centimeters taller in one year during this stage. The pubic hair will continue to thicken and darken. Hair will also show up under the arms about two years after pubic hair starts to grow, your voice will finish changing, and cystic acne could make its debut. The penis will continue to grow in width and length, and the testicles will enlarge slightly. This stage could happen any time between just after you turn 13 to when you're almost 16.

By Stage 5, you're probably as tall as you're going to get. Your penis and testicles are at their mature sizes, and you've had your deeper voice for a while. You'll get to start shaving, as facial hair will appear on the sides of the face, and your body will have a more adult shape overall, with wider shoulders and more muscle mass. Pubic hair will spread to the tops of the thighs. The major changes are complete. Your muscles may continue to grow. This stage generally happens between 15 and 17.

Boys enter and progress through the stages of puberty at different rates, so don't worry if you're not hitting the growth spurts and getting your first introduction to shaving as early as some of your friends. If you do think something is out of the ordinary, however, don't be afraid to address concerns with your doctor. He'll be able to do the appropriate tests to rule out any abnormalities.