Quilt block cutting calculator

Square-in-a-Square Calculator

Get the center and corner cut sizes and total pieces for your stitch-and-flip blocks.

Plan Your Square-in-a-Square Blocks

For the Stitch-and-flip / folded corners method only.

Cut These Pieces

For 1 block

Center squares

Cut 1

4 1/2" × 4 1/2" each

Corner squares

Cut 4

2 1/2" × 2 1/2" each

Each block should measure 4 1/2" unfinished after assembly.

Stitch-and-flip: mark the diagonal, sew on the line, trim about 1/4" beyond it, then flip and press.

Common Square-in-a-Square Cut Sizes

Finished BlockCenter Square CutCorner Square Cut
2"2 1/2"1 1/2"
3"3 1/2"2"
4"4 1/2"2 1/2"
5"5 1/2"3"
6"6 1/2"3 1/2"
8"8 1/2"4 1/2"

How This Estimate Works

This calculator uses stitch-and-flip folded corners with standard 1/4" seams. It does not cover loose triangles, paper piecing, specialty rulers, or trim-to methods.

FAQ

Finished size is the part you see after the block is sewn into the quilt. The unfinished block is 1/2 inch larger to include the standard seam allowance.

Patterns may use a different construction method, seam allowance, or trimming step. Follow the pattern when it gives its own cutting instructions.

No. It supports only the stitch-and-flip, folded-corner method with standard 1/4-inch seams.

Sew on the marked diagonal line. Afterward, trim the outer corner so about a 1/4-inch seam allowance remains.