Start with the cut size
Enter the size of each piece before sewing, including the seam allowance your pattern needs. For example, a square finishing at 4½ inches with ¼-inch seams on every side is cut at 5 inches. The calculator does not add seam allowances to your dimensions.
Use the fabric width you can actually cut after removing selvages and any unusable edges. The starting 40-inch width is an editable example, not a promise about your fabric. Inputs can use inches or centimeters; switching units converts the dimensions.
A strip-by-strip plan
The calculator fits complete pieces across the width, then rounds the number of strips up. Forty 5-inch squares across 40-inch usable fabric need eight squares per strip and five strips: 25 inches of fabric length, before any chosen extra. Purchase rounding makes that ¾ yard or 0.7 meter, depending on how you buy.
Extra fabric length is added once after the calculated strips. Choose your own allowance for straightening the first edge or trimming; it is separate from the cut dimensions. The last strip may need fewer pieces than the others. Its unused positions are spare fabric, not extra pieces you have to cut.
Check the grain and print before rotating
“Keep cut width across the fabric” preserves the entered orientation. “Turn every piece 90°” swaps width and length for every piece. “Compare both orientations” chooses the shorter of those two uniform row layouts. Only allow turning if your pattern’s grainline, nap and print permit it.
This tool does not combine orientations within one layout or optimize pieces into side offcuts. For multiple sizes, calculate each group separately and review how they share fabric. It does not handle curved pieces, bias strips, pattern matching, shrinkage or garment pattern layouts.
Buy in your shop’s increments
Yards round upward to ⅛ yard; meters round upward to 0.1 meter. Each rounds independently from the unrounded required length, so the two recommended cuts can represent different amounts of spare fabric. Ask for at least the displayed amount and check the increments your shop sells. The row drawing is a schematic, not a cutting template.