Solvi Quilting

Quilt sashing calculator

Enter the block size, the grid, and the sashing width. The calculator counts the vertical strips, the horizontal strips, and the cornerstones, sizes every cut, totals the yardage, and gives the finished top size the sashed grid produces, with an optional frame around the whole grid.

Usable width is the nominal width minus 2 in for selvedges and squaring.
Finished quilt top size54 in x 68 in
Sashing strip, between blocks x 152 4/8 in x 12 4/8 in cut
Sashing strip, between rows (segment) x 162 4/8 in x 12 4/8 in cut
Cornerstone square x 122 4/8 in x 2 4/8 in cut
Exact yardage3/4 yd
Buy7/8 yd
Or cut it from fat quarters4 fat quarters

Cutting plan

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Bolt view: 42 in usable wide by 27 4/8 in long, drawn to scale. Shaded bands are leftover inside the purchased length: 111 sq in (0.77 sq ft). Dashed outlines are segmented strips that get joined end to end.

  • Cut a 12 4/8 in strip: Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; Sashing strip, between rows (segment), 2 4/8 in long; leftover 2 in wide
  • Cut a 2 4/8 in strip: Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Cornerstone square, 2 4/8 in long; leftover 2 in wide
  • Cut a 2 4/8 in strip: Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Cornerstone square, 2 4/8 in long; leftover 2 in wide
  • Cut a 2 4/8 in strip: Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Cornerstone square, 2 4/8 in long; leftover 2 in wide
  • Cut a 2 4/8 in strip: Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Cornerstone square, 2 4/8 in long; leftover 2 in wide
  • Cut a 2 4/8 in strip: Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Sashing strip, between blocks, 12 4/8 in long; Cornerstone square, 2 4/8 in long; leftover 2 in wide
  • Cut a 2 4/8 in strip: Cornerstone square, 2 4/8 in long; Cornerstone square, 2 4/8 in long; Cornerstone square, 2 4/8 in long; Cornerstone square, 2 4/8 in long; Cornerstone square, 2 4/8 in long; Cornerstone square, 2 4/8 in long; Cornerstone square, 2 4/8 in long; leftover 24 4/8 in wide

The formula, in words

Vertical sashing strips sit between the columns: there are (columns minus 1) lines of them, one strip per row in each line, cut to the sashing width plus seam allowances by the block height. Horizontal strips sit between the rows: (rows minus 1) lines, one per column, cut by the block width. With cornerstones, each crossing takes a square cut at the sashing width, and there are (columns minus 1) times (rows minus 1) crossings. Without cornerstones the horizontal strips run continuous across the full sashed width instead. A frame is one more round of strips around the finished grid.

Worked example

Twelve inch blocks in a 4 by 5 grid with 2 in sashing and cornerstones: 15 vertical strips between the columns, 16 horizontal strips between the rows, and 12 cornerstones at the crossings. The sashed top finishes at 54 x 68 in, ready for borders, binding, and backing to be figured from that size.

Questions quilters ask

What do cornerstones do?

A cornerstone is the small square where a vertical and a horizontal sashing strip cross. It breaks the long horizontal strips into block-width segments, which keeps the grid easier to align and adds a design accent, often in a contrast fabric. Without them, the horizontal strips run the full width in one piece.

How wide should sashing be?

Between 1 and 3 in finished is the common range for bed quilts. Narrow sashing, 1 to 1.5 in, just separates busy blocks. Wider sashing, 2 to 3 in, gives plain blocks room and adds real size: 2 in sashing on a 4 by 5 grid adds 6 in of width and 8 in of length.

What is the frame option?

A frame is a strip of sashing fabric run around the outside of the whole sashed grid, before any borders. Patterns often call for it to stabilize the grid edge and give the eye a resting line. It is counted and cut with the sashing here.

Does sashing count toward the block size?

No. Block sizes here are finished sizes, and the sashing sits between them, so the top grows by the sashing widths between every pair of blocks. The finished top size shown is blocks plus sashing, which is the number the border, binding, and backing calculators need.