My hand width across the base knuckles is right at 4.2 inches, actually. But then I wear a XXL to XXXL glove. That's why I seldom take pictures where I'm holding my dick, makes it look a lot smaller than it really is.
Some time ago in a blog about girth I was challenged over the first pic attached here, with the idea being that it would be easy to pinch a fold into the tape where it's hidden under my cock. So I took the second photo attached here and told the blogger to take his ruler to Walgreens and see if the object wasn't really 1-11/16 inches in diameter (5.3 inch girth).
That second photo has become my favorite household item comparison but I wouldn't necessarily recommend the stunt. Had to run cold water over my crotch for several minutes before I was able to get the damned thing off!
.