This really has to be one of the most overdone conversations on this board. See here:
http://www.lpsg.org/85887-who-has-biggest-cock-world.html and about half a dozen other threads.
To summarise the position as I understand it:
Mandingo - estimated at between 10 and 11 inches
Lex Steele - usually claimed to be 11-12 inches and up, measured on film at 9.5 inches, shrugged and accepted it
Ramon from Monsters of Cock - photo shows him measured at a tad over 8 inches
John Holmes - estimates vary from 8 inches to a (self measured) 10 inches
• If there are real penises measuring over 11 inches, much less 12 and up, we've yet to see more than anecdotal evidence of them. And though bell curve projections imply there ought to be a thousand or so such monsters in the United States,
not one of those people appears to have gone into porn, or been convincingly photographed. Which implies either
that these penile gods are all inexplicably modest; [ii] that no one over 11" can get it up; or [iii] that the bell curve figures have been incorrectly extrapolated, quite possibly as a result of incorporating studies in which the subjects were permitted to submit unchecked self measurements.
• Members of this board claiming to be 11" and up - equally inexplicably - tend to be members who modestly refrain from posting their pics to the gallery.
• People are really, really bad at making accurate guesstimates based purely on visual evidence, and porn film "measurements," with the rare exceptions of those mentioned above, are invariably fudged.
• Modern morphing and photoshop technology makes photo/video evidence increasingly unreliable.
• Although the claims made in big dick porn and, sadly, on this site tend to obscure it, the fact is that a real 10 inch cock is absolutely freakin' enormous.
I'd be happy to be proved wrong.