All those calculations on the first page were done under the assumption that the penis is perfectly cylindrical, which it is not for most people. Mine is rather wide and flat. I have a 5.1 girth, yet I have a 1.7 diameter, which is wider than it would be if it were cylindrical. I’m curious if women care about the penis being thicker in the horizontal direction or in the vertical direction.
1.7*3.14 = 5.33, near enough to your girth to be a very good aproximation.