Calculating required border lengths for multiple borders and mitered corners
I want to add 3 borders to my quilt top .... 1st one 1" (finished), 2nd one 2.5" (finished), 3rd one 3.5" (finished). I need to calculate the fabric required for each border BEFORE I start this process as I might be short on the final border. I want to make sure I have enough fabric before I start - instead of getting 3/4 of the way done and then finding out I don't have enough. Is there a formula out there so you know exactly how much yardage is needed prior to planning on the multiple mitered border?