Here is the Male Iron Helmet from Skyrim. The helmet is measured to about 13 inches. I'm slowly working on armor, and will probably do helmets first. This is not the demo helmet.
we built this one while on a long boat trip a few weeks ago - I found out why you need to pay attention to scale! I am really new to Pepakura, so I just figured you hit print, then put it all together. Wrong. This helmet turned out comedically large - it was ginormous! It had to be about 28 inches from top to bottom, so we are going to use it for a decoration in my son's room!