Questions:
Joey (15-17) asks about penis size: Generally, how old are teenage guys when their penis starts to get bigger?

…and so does Peter (12-14): My penis when erect is about 3 inches long. Is that normal or big or small?

…and so does Will (20): I am almost 20 years old, and I still haven’t fully matured. Is this ok, do some people take longer to develop, is there a cut-off date for growth or something? My penis size isn’t that great, and I don’t think it has grown completely or as much as it should have. The only other thing that makes me worry is the fact that everyone says I look like I am 16, and I hate that, it gets to you after awhile. Everything else is ok, the voice changed, and I have all the hair and all. Just the one thing that worries me.

…and so does Nick (15): What is the normal size of an erect penis for a 15 year old male?

…and so does Jason (14): I’m 14 and my penis is 4 inches long when it is erected, it this normal, small or big for my age?

…and so does Brian (17): In the locker room sometimes glancing in the wrong spots I can see other guys’ penises. What is the average size for someone who is seventeen years of age? How should I feel about the size of mine compared to others?

Answer: Penis size growth typically doesn’t start until around 11-16 years of age (average: 13-14). Normal penis size covers a wide range, and the average size is probably smaller than you think: about 3 to 4 inches (about 9 cm) in a non-erect, mature male. As there are boys with penises larger (perhaps twice that size), there are also boys who have smaller, and still normal, sized penises. When you’re an adult, you’ll learn that size doesn’t matter so much, but it still can be very frustrating! Try not to worry about it if you think you’re “too small” — appreciate what you have! If the other boys tease you, just say “heh, it’s not the size that matters, it’s what you do with it!”

Question: Tianyao (m, 13):I am 13 years old, going to 14. I still do not have any pubic hair although my other friends who are shorter than me already have. My penis is very short, only about 6.5 cm (about 2.5 inches) when erected. Are there any problems with me?

Answer: It must be very frustrating to seemingly be behind in your growth than your friends. But let me assure you that you are still normal and there is probably nothing wrong. Puberty in boys usually begins between the ages of 9 to 15, with the average about 12 or 13. If you are noticing growth in height and weight, then rest easy that you will begin to grow in other areas soon.


Question: Hi my name is Bernard and I was wondering I have a small penis and I am 13 and sometimes my penis gets so small it the size of a 2 year olds and I have a cousin who is 1 month younger then me whose penis is very big for his age maybe he is size of an adults when erected maybe smaller then an erected adult about the same size and all the man in my family have pretty big penis`s and I am wondering if my weight can affect the size because I weight 171 pounds and my doctor says I am 40-50 pounds over weight can that affect the size
p.s. And if so if I lose the weight will I see any difference?

Answer: Hi Bernard,
For starters, you’re 13, you still have PLENTY of time still to grow penis-size wise. It’s sometimes best not to compare yourself to others, especially at your age, because everyone develops differently, and some may be farther into puberty than you, which will make the comparison not worthy of consideration. You may think you have a small penis, but you may actually have an average, or even above average penis. We can’t tell you how you compare without the actual measurement. The average size for the ADULT male is around 5-6″, but for your age, there is no statistical average because of the fact that everyone develops differently, as I mentioned above. Weight can affect your appeared penis size, but not your true penis size, only genetics affects your true penis size. If you’re severely overweight or obese, the folds of fat can push onto your penis and make less of it visible from the outside. Now, don’t worry about your weight at your age unless your doctor has concerns. Being that much overweight can have problems if you are older, but you still have time that you will grow in height, and you will most likely fill out and become less fat. Losing weight around the pubic area will make your penis show more, but again, don’t worry too much about your weight and how it affects your penis size at your age. If your doctor feels you need to lose weight, he will be the best one to tell you the best options. Just relax and go with the flow, everything will work out in time.

Credit: J. Geoff Malta, MA, EdM, NCC Adolescent Therapist