Is there a formula for figuring fence board width? I'd like all of my fence boards to be the same width with the same spacing. Let's say I want to build a fence panel that is 6ft.3in. wide, with 3/16th spacing between the boards, and 3/16 on each end of the panel, next to the posts. I'm using fence boards that are 5.5 inches wide - how much do I rip each board?