Square in a Square Quilt Block — Cutting Chart for Any Size

2 fabrics · Difficulty 3 of 5

Square in a Square is a 1×1 block of 5 pieces. Cut sizes for 4″, 8″, 12″, 16″, 20″ are below; for any other size it divides into cleanly, type the size and the chart recomputes.

Set the finished size

At a glance

Grid
1×1
Pieces you cut
3 — subcutting turns them into the 5 in the sewn block
Difficulty
3 of 5 — confident beginner How this is scored

Set the size

Cutting sizes for a 12″ finished block.
Centre squares — Fabric A
9″
Corner squares — Background
6⅞″
Square in a Square quilt blockA 1 by 1 grid of 1 unit: 1 square-in-a-square unit. 5 pieces in total.
Square in a Square — a 1 by 1 grid of 1 unit: 1 square-in-a-square unit. 5 pieces in total.

Reading focusOuter trim and inner diamond boundaries stay distinctsquare-in-a-square unit

Construction lattice
1 module wide × 1 module high
Unit mix
square-in-a-square unit
Piece count
3 to cut · 5 in the diagram

Cut these pieces

Column headings are the FINISHED block size — the size it will be once it is sewn. Every number in the table is the size to CUT, which includes ¼″ of seam allowance on each edge. Rows that are subcut on a diagonal are cut larger still, so the allowance survives the extra cuts.

Scroll sideways to see every size.

Cutting sizes for Square in a Square, by finished block size
Patch4″8″12″16″20″
Centre squares — Fabric ACut 13⅜″6¼″9″11⅞″14¾″
Corner squares — BackgroundCut 2, cut once on the diagonal2⅞″4⅞″6⅞″8⅞″10⅞″

Read the block

Match each fabric letter in the diagram to the same fabric name in the cutting table. The caption describes the generated geometry in text.

Fabrics in this block

  • A — gold
  • BG — background

Which sizes divide cleanly

Scroll sideways to see every column.

Which finished sizes each grid divides into cleanly
GridDivides cleanly atThe first few sizes
1×1this blockevery ½″½″, 1″, 1½″, 2″, 2½″, 3″ …
2×2every 1″1″, 2″, 3″, 4″, 5″, 6″ …
3×3every 1½″1½″, 3″, 4½″, 6″, 7½″, 9″ …
4×4every 2″2″, 4″, 6″, 8″, 10″, 12″ …
5×5every 2½″2½″, 5″, 7½″, 10″, 12½″, 15″ …
7×7every 3½″3½″, 7″, 10½″, 14″, 17½″, 21″
  • A 5-patch block at 12″ would need 2.4″ units, which is not a mark on any ruler. Try 10″ or 12½″ instead — Sister's Choice is the 5-patch block on this site.
  • A 7-patch block at 12″ would need 1.714…″ units, which is not a mark on any ruler. Try 10½″ or 14″ instead — Bear's Paw is the 7-patch block on this site.

More about the sizes that do not divide cleanly

The sizes in between

Every whole-inch Square in a Square size from 4″ to 20″ can be cut accurately on its 1×1 grid.

These sizes divide cleanly but sit between the main chart's columns — the same computed cuts, published here so they exist on paper too. Any other clean size still computes in the size input above.

Column headings are the FINISHED block size — the size it will be once it is sewn. Every number in the table is the size to CUT, which includes ¼″ of seam allowance on each edge. Rows that are subcut on a diagonal are cut larger still, so the allowance survives the extra cuts.

Scroll sideways to see every size.

Cutting sizes for Square in a Square — between sizes, by finished block size
Patch9″10″11″13″14″15″
Centre squares — Fabric ACut 16⅞″7⅝″8⅜″9¾″10½″11⅛″
Corner squares — BackgroundCut 2, cut once on the diagonal5⅜″5⅞″6⅜″7⅜″7⅞″8⅜″

About this block

Pieces in the finished block
5
Unit types
square-in-a-square unit
Divides cleanly at
½″, 1″, 1½″, 2″, 2½″, 3″, 3½″, 4″, 4½″, 5″, 5½″, 6″, 6½″, 7″, 7½″, 8″, 8½″, 9″, 9½″, 10″, 10½″, 11″, 11½″, 12″, 12½″, 13″, 13½″, 14″, 14½″, 15″, 15½″, 16″, 16½″, 17″, 17½″, 18″, 18½″, 19″, 19½″, 20″, 20½″ and 21″ finished.
Also known as
Square in Square, Diamond in a Square
Fabric for one 12″ block
½ yd total, rounded up to the nearest ⅛ yard, assuming 40″ of usable width.

One unit is the entire block: a centre square set on point inside corner triangles, no internal grid at all. The centre's corners must land at the midpoint of each side, and its points need seam allowance preserved beyond them when the block joins the top. The corner triangles' long edges are bias — sew them without stretching and press away from the centre.

Piecing order

  1. Make the 1 square-in-a-square unit.

  2. Lay out row 1 of 1 and sew its pieces together, left to right.

Cutting oversize

The chart gives the standard cut sizes, nothing padded. Some quilters cut this block's triangle units a little oversize and trim back — published allowances genuinely disagree on how much, so the range with its sources is on how to square up a quilt block.

History

The naming is genuinely contested, and this page does not pretend otherwise. The one-round block is commonly called Square in a Square or Diamond in a Square; its multi-round relative carries the encyclopedia-documented Economy names — Economy Patch, Thrift Block, This and That — with roots in the 1897 Ladies Art Company catalog and the Economy Patch name credited to Carrie Hall and Rose Kretsinger's 1935 book. Usage overlaps in both directions, and sources disagree about where one block ends and the other begins.

Sources: Generations Quilt Patterns — Economy Block; Scrapish — Economy Block.


Common questions

What size can I make Square in a Square?

Any size it divides cleanly: ½″, 1″, 1½″, 2″, 2½″, 3″, 3½″, 4″, 4½″, 5″, 5½″, 6″, 6½″, 7″, 7½″, 8″, 8½″, 9″, 9½″, 10″, 10½″, 11″, 11½″, 12″, 12½″, 13″, 13½″, 14″, 14½″, 15″, 15½″, 16″, 16½″, 17″, 17½″, 18″, 18½″, 19″, 19½″, 20″, 20½″ and 21″ finished. The chart above carries 4″, 8″, 12″, 16″, 20″ ready-worked, and the size input computes any other clean size without you doing arithmetic — every value computed by Quilt Block Atlas, none transcribed.

How many pieces are in a Square in a Square block?

5 pieces make up the sewn block, but you cut 3. The difference is method: triangle units are cut as squares and subcut, so the chart's quantities are what your rotary cutter produces, not what you count in the diagram.

What sizes does a 1×1 block divide into cleanly?

½″, 1″, 1½″, 2″, 2½″, 3″, 3½″, 4″, 4½″, 5″, 5½″, 6″, 6½″, 7″, 7½″, 8″, 8½″, 9″, 9½″, 10″, 10½″, 11″, 11½″, 12″, 12½″, 13″, 13½″, 14″, 14½″, 15″, 15½″, 16″, 16½″, 17″, 17½″, 18″, 18½″, 19″, 19½″, 20″, 20½″ and 21″ finished. The step is half the grid this block's cutting sizes are computed on, and the clean-size table above marks this block's row with the other families beside it.

Is Square in a Square good for a beginner?

It makes a fine early block, though not a first one — it scores 3 of 5, confident beginner, on this site's computed scale: 5 pieces, with the square-in-a-square unit as its hardest unit. The scoring rule, and every block ranked by it, is on the difficulty page linked above.

How do finished size, sewn unfinished/trim size, and starting cut size differ?

Finished size is 12″ after the block is sewn into surrounding seams. Its sewn unfinished/trim size is 12½″ before those outer seams, derived with the plain-square allowance. Starting cut size is the method-specific input listed in the chart. Starting cut size equals the unfinished outer target only for a plain square or rectangle workflow; it is not generally the same for pieced triangle units.


Keep going


Measure this square before you cut. It must be exactly 1 inch. If it isn't, your printer scaled the page — reprint at 100% or "Actual size", not "Fit to page".

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