here is the link: 10 Surprising Sex Statistics | LiveScience #9 states that the average length of an erect penis is 5-7 inches. for girth it is 4-6 inches. source is the kinsey institute which is in the United States. actually indiana university, bloomington, indiana. i'm a hoosier. just thought i would put it out there. i know some people may think kinsey's study's are skewed though.