Don't know about a chart, but if you cut the HST into 4 strips, you would subtract 2 inches from the RAW HST size, for the width and 1/2' from the height. So if you start with a raw 8.5" HST, cut it into 4 equal strips (2 1/8"), and sew them back together, you wind up with a rectangle 7X8.5. When you put that into a quilt, your block finishes at 6.5X8