To finish your binding at 5/8"' cut it originally at 3". Fold in half and press; now it is 1.75". Sew to the front of the quilt with a 1/4" seam allowance; 1.25" left. Fold over to the stitching line on the back and sew it down and the finished width should be 5/8". You might actually want to cut at 3 1/4" to have a little to wrap around the edge.