how big is it. when you compare it to a piece of paper from a notebook? 4 answers by real people - how big is 20 inches? GetTopUp Team 9 days ago Since there are 2.54 centimeters in an inch… 2.54 x 20 = 50.8 centimeters, half a meter, about two sheets of paper 0 Anonymous 9 days ago A sheet of notebook or computer printout paper is 8 1/2 by 11 So the 2 sides add up to 19 1/2 inches. 0 Anonymous 6 days ago This Site Might Help You. RE: how big is 20 inches? how big is it. when you compare it to a piece of paper from a notebook? 0 ? 9 days ago the size of my dick nah 15cm is 6 inches so can you go from there? 1