How big is your penis when you are 14 years old?
That is going to depend upon several factors, such as what stage of puberty you are in at age 14, some boys develop later or earlier than their peers. Also, your genes will play an important part in this as well. Some boys grow to nearly adult size by the time they are 14, and others lag behind. It is impossible to forecast just how big you will be at any given age, but you can rest asssured that you will be bigger than when you were a little boy, and probably grow some more after that, but that is about as close as it can be narrowed down! So relax, your penis will be however big it is meant to be, and as long as it works well, and brings you pleasure, the size is of little import.
The average penis size for a 14 year old is about 4 inches. HOWEVER, the age at which puberty typically begins is anywhere between 10 and 15 years old. So the penis size for a 14 year old can range from prepubertal (About 2 inches) to Adult (6+ inches). At 14 years old it would be normal to have a penis anywhere in that range.