I am not sure you have given enought information. Are you using 2.5" strips in your quilt?? I have drawn this outline on EQ. I THINK that the quilt width will be 30.5" x 48.5". If you are using 2" stripes, you want the lenght and width of you quilt (minus seam allowance) to be dividiable by 2"The measurement are 8" between you top and the size you want the quilt to be. That is 4" finsihed border of all sides. I have floated the quilts with a 1" light border then used the 2" stripes cut in the lenght of 3.5" for a finsihed 3" border. Hope this is what you wanted to know.