The average length is about 6 or 7. There is no way to increase the length, other than surgery, but I hear that those things are risky and can end in your piece getting pretty mangled furthermore there are no actual proven cases that I have found yet that confirm that it actually works, and from the stories I hear it only ads like another inch. For that I think the price and the risk are too high.
Penn and Teller did a show about other methods once. I think they covered pumps, pills and exercises, all have been proven to be bullsh!t, and anything other than the pill was just plainly uncomfortable. Sounds to me like yet another waist of time and money, but at least no risk of getting your junk mangled.
Anyway whatever your size unless you're just an inch height P.I. then don't worry too much about it. The thing is it's just not that important. Besides isn't the G-Spot only like a couple inches in anyway?
The average penis length is 5-6 inches. There is no real way to increase the length. Pills and pumps only really help with impotence. The length of your penis doesn't really matter because most of a woman's nerve endings are within the first 3-4 inches of her vagina. Furthermore, it isn't really the size of your dick as much as it is how you use it.