Feb 17, BIG hands, big penis? We reveal the real way to guess a man's schlong size. Jun 30, I can grip around a 7", circular stiff girth just barely and I have pretty average man hands. I don't think you're right about " circumference of. How much does the size of penis matter during intercourse and what is the minimum sized penis that can fully satisfy a woman? that you're having sex with that you have the tools necessary for the completion of the job at hand. Eugene S. Robinson, Editor-at-LargeFollow Eugene S. Robinson on Facebook Follow.