Free quilting calculator

Fit a pieced quilt border with plain spacer strips

For quilters adding a border made from repeated square blocks to an already pieced rectangular quilt. Keep a block at each corner, use whole blocks along every side, and see the plain spacer widths that fill the remaining space.

Example

A 43 × 58 in finished center with 6 in finished blocks uses 8 blocks across and 10 down between four corner blocks. The spacer strips finish at 2.5 in on the left and right and 1 in at the top and bottom. The outer quilt finishes at 60 × 72 in, with 40 border blocks total.

What this covers: square repeat blocks and four matching square corner blocks. Measure a sewn sample before cutting. This is a dimension plan, not a component cutting pattern or fabric yardage estimate; complex patchwork blocks can have different component cut sizes.

Enter your quilt and block measurements

Center width in Center height in How did you measure the center? Finished size of one square border block in Seam allowance on each edge

The default measurements are 43.5 × 58.5 in edge to edge. With a 1/4 in seam allowance, the finished center is 43 × 58 in.

Add extra whole blocks to make wider spacer strips

The planner first uses the fewest whole blocks that cover each finished center dimension. Add extra blocks to widen the plain spacers. Extra blocks go between the corner blocks on both matching sides.

Extra blocks across each top and bottom Extra blocks down each left and right side

How the spacer strips make the blocks fit

The center sits inside a plain spacer frame. Whole square blocks make the pieced border outside that frame, with one corner block at each corner. The left and right spacer widths share any extra width across the top and bottom block runs. The top and bottom spacer widths share any extra height across the side runs.

For a 43 × 58 in center and 6 in blocks, eight blocks span 48 in across and ten span 60 in down. The differences are 5 in and 2 in, so each left/right spacer finishes 2.5 in wide and each top/bottom spacer finishes 1 in wide.

Finished measurements describe the sewn size without seam allowances. For a spacer strip with a 1/4 in seam on both long edges, add 1/2 in to its finished width before cutting. A plain 6 in square corner block can be cut at 6.5 in for quarter-inch seams. For a pieced repeat block, 6.5 in is its unfinished assembled size, not a cut size for the pieces inside it.

The planner uses nominal dimensions. Sew and measure a sample repeat and corner unit first, since construction can change their real size. Displayed calculations round to 0.001 in when needed; check the sample and measurements before cutting.

Your measurements stay in this browser

Calculations run on this device. Optional, privacy-focused page and button counts do not include quilt dimensions, block sizes, seam allowances, or spacer measurements. Analytics are disabled in local previews and automated browser checks.