If you don't like charts, and do not need to have precise dimension of what the front or back focus are, there is an even simpler solution, pointed out this week. It's the batteries test. Put batteries (at least 3 of them) in a 45 degree position. If your lens is a telephoto and cannot focus close enough, use coke cans or bigger similar objects. Aim the center focus at the center battery and see what is in focus. That's as simple as it gets.