Free quilting calculator

Square in a Square Calculator

Four triangles folded onto a center square, meeting in the middle. This is the stitch-and-flip version: no templates, just a center and four smaller squares.

A square-in-a-square quilt block whose four corner seams meet in the center
The corner seams of a square in a square meet in the middle, so the center reads as a diamond.

A 6 inch finished square in a square. One block.

Why the corner seams have to meet

A square in a square is four triangles folded onto a center square, meeting in the middle. The center reads as a diamond. This is the stitch-and-flip version: no templates, just a center and four smaller squares. Draw a diagonal on each corner square, or press the fold after sewing. The seam runs from the midpoint of one side of the center to the midpoint of the next.

If the seams miss the middle, the corner square was the wrong size or the seam allowance wandered. A snowball is the smaller version of the same idea: the corners are meant not to meet, and a square of the center fabric still shows. That cut is on the snowball calculator.

How the squares are calculated

The dog-ears at the corners are supposed to be there until you trim them. Trim the block to the unfinished size when the corners are on.

Square in a square cutting chart

One block needs one center and four corner squares.

Finished blockCenter squareEach corner square
4 in4 1/2 in2 1/2 in
6 in6 1/2 in3 1/2 in
8 in8 1/2 in4 1/2 in
12 in12 1/2 in6 1/2 in

How to use this calculator

  1. Enter the finished block. A 6 inch block wants a 6 1/2 inch center and four 3 1/2 inch corners.
  2. Enter how many blocks you are making. The card multiplies the corners by four per block.
  3. Sew a corner to opposite sides of the center, flip, press, then sew the other pair. The four seams should meet in the middle.
  4. Trim to the unfinished size and clip the dog-ears.

Tips for the meeting point

When the piece is part of a whole quilt. Economy blocks and square-in-a-square chains are this unit repeated. The count on the card is the cutting list. The fabric calculator counts every piece in a design, then adds binding, backing, and batting. These pages answer one question at a time.

Related calculators

Square in a square FAQ

What size are the squares for a square in a square?

Cut the center the finished size plus 1/2 inch. Cut four corner squares at half the finished size plus 1/2 inch. Sew them to the center and trim the block to the finished size plus 1/2 inch.

How is a square in a square different from a snowball?

On a square in a square the corner seams meet in the middle, so the center reads as a diamond. On a snowball the corners are smaller and a square of the center fabric still shows.

Design the quilt, then let the yardage follow

These calculators answer one question at a time. The studio counts every piece in a design, including binding, backing, and batting.

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