How big is the average penis? Every source I look is different.
The average, flaccid penis length is 3.5 inches - and the average, erect penis is 6 inches. The average penis girth is 4.5 inches in circumference. *However,* most of this information comes from voluntary polling, which may suggest that there is some exaggeration on the part of reporters (about 50% of people with penises express desire for a larger organ!). Also, flaccid penises have a lot more variability than erect penises (apparently, some people call an erection the 'great male equalizer') - so urinals or locker rooms (or other places with public, flaccid penises) is no place for comparison!
Like the perceived number of sexually active peers, most people overestimate the average penis size (in fact, 85% of men, according to one pole, overestimate) - and this can lead to a lot of needless anxiety. Regardless, wherever someone falls along the penis size spectrum, there are so many (more important) factors to what goes on with your penis. It *is* how you use it, not how big it is!
Hope that helps (there is a lot of variation...and we can't find a median or standard deviation for these values...alas.)