Sashing and cornerstone plan

How to use it

1. Enter block rows and columns, finished block dimensions and finished sashing width.
2. Set seam allowance, outside sashing and cornerstone choices.
3. Choose whether long sashing runs may use straight joins.
4. Enter separate usable widths and purchase increments for sashing and cornerstones.

Formula and variables

Cut strip width = finished sashing width + 2 × seam allowance. Internal line counts come from the block grid; outside sashing adds two lines on that axis. Sashing and cornerstone strip counts are calculated independently from their usable widths. Yardage = full-width strip count × cut strip width ÷ 36.

Block rows and columnsblocks

Counts of finished blocks in a rectangular grid.

Sashing widthin

Finished visible sashing width before seam allowances.

Outside sashingyes/no

Whether two additional lines are added along each grid axis.

Independent example

A 2 × 2 grid of 6.5 in blocks, 2.5 in sashing, 1/4 in seam per edge, no outside sashing, with cornerstones.

There is one vertical and one horizontal internal line. Each makes two sashing pieces, so four 7 in cuts are needed. Six pieces fit across 42 in, requiring one strip. One cornerstone also fits in one strip. Each role uses 3 ÷ 36 = 0.0833 yd; each rounds to 0.25 yd.

• 4 sashing pieces
• 1 cornerstone
• 0.083 yd theoretical per role
• 0.25 yd purchase per role

What the result means

Sashing and cornerstones have separate counts, usable widths and purchase rounding. The grid model does not optimize mixed-size nesting or pattern-specific construction.

Common questions