This site had potential, but fell apart for me when it claimed Lexington Steele was 11" long and Ron Jeremy is 10". Seems totally made up considering the very intelligent posters here at LPSG estimated the largest penis in porn, Mr. Mandingo to be 10.6" long, and anyone who has ever seen a West Coast Productions movie can see that Mandingo is slightly longer than Lex. And don't even get me started on Ron Jeremy. Sure he was considered big compared to the tiny pornstars of the 80's, but by today's standards her barely measures up. And his "apparent" length is enhanced by his relative lack of girth. I would estimate Ron at about 7.5x5.5.
I think the problem with this site is that they must be assuming you are measuring from the bottom. Another problem is that they are using completely unreliable data - from users that are going to either guess their size, incorrectly measure, or lie about it.
Anyway that was my rant.