the size of the binding you cut varies according to how big you want the final binding to be. I prefer a final binding width of 3/8 of an inch (I'll do 1/4 inch on very small quilts but I don't do too many of them). I use the formula of multiplying the finished width times 7 (to accommodate for the folding and turning) then, as I mentioned in an earlier post, I add a quarter of an inch since I do machine finishing from the front (this extra ensures that I catch the edge in the back without a lot of stress on my part). Therefore, for 3/8 finished the numbers are: 3/8 times 7 equals 21/8 or 2 and 5/8 then I add the 1/4 inch for a total cut width of 2 and 7/8. (I even make it easier on my self and just cut 3 inches if I feel like it.) For a 1/4 inch finished binding multiply by 7 which equals 1 and 3/4 inch cut width..then for my own ease, add 1/4 inch to equal 2 inch cut strip width. I actually consider each project individually before I cut because thee may be variations based on seam allowances on the edge (if there is no border) weight/thickness of batting, etc. The bulkier the quilt sandwich is at the edge the more inclined I am to give myself an extra 1/8th of an inch to work with. Again, I stitch everything from the front so I can control what the front side will look like....and the extra I have is covered nicely by an decorative stitch I choose to use.