Distribute guides evenly in Photoshop
I'm trying to make a color chart for someone that would be four thumbnails across and four thumbnails down. Now, this seems simple, but there is too much math and calculator work to try and get this to work. Ideally, I'd love to account some gutters/margins, but I just can't figure it out. I found this article from 2006 that seemed perfect, until I couldn't find the option listed there.
EXAMPLE (Not evenly distributed):
Does anyone else know how to do this?