Originally Posted by Ultimatum
I think alot of it falls down to the insecurity of your own penis. Otherwise that question wouldn't be asked.
To an extent it does matter, a girl isn't going to orgasm of a 1 inch penis is she. I would say average+, but i guess its up to the girls to decide what really is 'big enough'.
Actually in many cases she probably wont orgasm just from the penis anyway. For most girls the important point of stimulation is the clitoris which is not affected by the length of the penis at all.