I agree with QuiltingCrazie that we all have our preferred methods and isn't that a nice thing. I like diagonal seams best. I took a class where the instructor said don't bother with the tape measure. Put the strips of border fabric across the middle of the quilt making sure all is smooth and not stretched, and whack them off. You then have two same size border pieces that you can ease in on the top and bottom. Do same for sides. Or sides first, etc.
Scissor Queen thanks for the formula.