It doesn't matter if you cut this size or if you add seam allowances, as long as you do the same thing for all borders.
This is based on the Fibonacci series of numbers, which actually goes like this:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...
(Hint for those of us who use the metric system - take this series above, but use centimeters instead of inches.)
If you strictly follow the series and use 2 one inch borders, make sure they have nice contrast. I personally prefer a half-inch or quarter-inch piping instead of two one inch borders most of the time.
I broke the true Fibonacci sequence to add values that would be good for piping, 0.25 inch and 0.5 inch. Based on the other border sizes you choose, you may like the larger piping better.
Just right-click to save the image below for your own use.