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Guys 101: The Penis

The penis and the scrotum are the male external sexual organs. This page is dedicated to young men who are making the transition from boyhood to adulthood. The penis is the source of much confusion during puberty, because it kind of takes on a mind of its own at times. The best thing you can do during this phase of your life is to learn what is happening to you so that you will not be freaked out by spontaneous erections, wet dreams, nocturnal orgasms, and/or growth spurts. This page is dedicated to making the transition from boy to adult easier and less confusing.

What The?

Many times during puberty, your penis may do things that you didn't know were possible, like becoming hard and popping up. When this first happens, you may think that something is seriously wrong with you, when in actuality you are experiencing something perfectly normal. Erections happen when your penis swells with blood and stiffens. Erections don't occur only in sexual situations: It is perfectly normal to get a "hard-on" (as erections are often called) just from your pants rubbing against you. Every male has erections, whether they are spontaneous or sexually related. Even though you may feel embarrassed as a result of your erection, try to remember that most people will not even notice it unless you draw attention to it. Erections are a NORMAL part of puberty and growing up! Don't be afraid! Puberty can be a tough time for boys, because not only does their voice transform from that of a child into an changes. The penis is a little difficult to understand at times since it can pop up at the oddest times. Because it sometimes seems to have a mind of its own and has many effects on male psychology, it is sometimes called the "little head."

Approximately a year after puberty begins, erections will start to be followed by ejaculation, which is when seminal fluid containing sperm comes out of your penis. This sticky liquid is not the same as urine (pee). The liquid is called semen, not urine, and it may cause yellowish spots to appear on your under-clothes and bed sheets. It's just a normal male experience.

Boys bodies produce sperm from the onset of puberty until the end of their lives, with new sperm developing inside the testicles every minute of the day (see male anatomy). There is a never-ending supply, and if the sperm are not used, they are absorbed by the body. There are millions of tiny little sperm within each drop of semen and usually, a teaspoon to a tablespoon of semen is released at a time.

If you do not ejaculate after having an erection, that is okay. The erection just goes away. It is not necessary to ejaculate each time you become erect.

Does Older = Bigger?

The penis grows and changes during puberty. When do you know that the growing has stopped and the penis is at its full length? Guys probably will not know the ultimate length until as late as age 17, though this age is variable. Most boys have a sense of how the changes in their bodies compare with the changes of other boys their age. The following table may reassure those of you who are in the early teens and are worried about measuring up to the average erect penis size of 6.25 inches. Average erection sizes by age are listed below.


Remember: These are just averages! They do not mean that you are abnormal if your measurements are smaller or larger. Every male is a unique person; it is okay if your penis is not the same size as the average! You should understand that the sizes of both the penis and testes vary among individuals.

Additional Information

For more information on this subject, check out www.teenwire.com, www.halcyon.com/elf/altsex/penis.html, and www.aap.org/family/puberty.htm.

Created March 3, 2006, last updated May 24, 2009