If you wanted a 8" block you would cut strips 2.5". Since this is basically a four x four, patch divided desired size by four then add seam allowance to each strip. I have a couple old book which really help me when I can't think one is "Taking the Math Out of Patchwork Quilting" and Mary Ellen Hopkins "It's OK to Sit on My Quilt" both out of print but great books for figuring strip size and settings.