Sashing Calculator
Zero Waste & No Sign-up: Calculate sashing strip quantities and yardage for any quilt layout. Enter block count, block size, and sashing width to get exact cutting requirements.
How to Use the Sashing Calculator
Enter your grid (columns and rows), block size, sashing width, and fabric width, and toggle cornerstones on or off. The calculator returns every strip count and cut size plus the yardage, and reports the finished quilt size: blocks plus the sashing strips between them.
Sashing strips are cut at the sashing width plus two seam allowances, and short strips are cut to the block length. With cornerstones, vertical strips number rows times columns-minus-one, horizontal strips number columns times rows-minus-one, and the cornerstone squares — cut to the same width as the sashing strips — fill the rows-minus-one by columns-minus-one intersections.
Without cornerstones the horizontal sashing runs the full quilt width in one piece, so the tool computes the long strip length and flags when it exceeds the fabric width and must be pieced. Yardage is then estimated using whichever cutting orientation wastes less fabric, rounded up to the next eighth of a yard.
Frequently Asked Questions
How many sashing strips does a 4 x 5 block quilt need?
With cornerstones: 15 vertical strips (5 rows times 3 gaps), 16 horizontal strips (4 columns times 4 gaps), and 12 cornerstones at the intersections. Without cornerstones, the horizontals become 4 full-width strips instead, which usually must be pieced.
What size are cornerstones cut?
Cornerstones are squares cut at the sashing width plus two seam allowances — the same as the sashing strip cut width — so they finish flush with the strips they meet. A 2-inch finished sashing at a quarter-inch seam uses 2-1/2 inch cornerstones.
How does sashing change the finished quilt size?
Each gap between blocks adds one sashing width: finished width equals columns times block size plus columns minus one sashing widths. Five 10-inch blocks across with 2-inch sashing finish 58 inches wide, and the calculator reports both finished dimensions.