Pinwheels & triangles · Confident beginner

Split Quarter-Square Triangle quilt block

One large triangle on one side of the diagonal and two small triangles on the other. Four of these make a Double Pinwheel.

Split Quarter-Square Triangle: main, background and accent. A 1 × 1 grid.

Cutting chart by block size

Fabric	Cut	Size	Then
Main	1 square	4 7/8" × 4 7/8"	1 triangles (cut once on the diagonal)
Background	1 square	5 1/4" × 5 1/4"	1 triangles (cut twice on the diagonal)
Accent	1 square	5 1/4" × 5 1/4"	1 triangles (cut twice on the diagonal)

Fabric	Cut	Size	Then
Main	1 square	6 7/8" × 6 7/8"	1 triangles (cut once on the diagonal)
Background	1 square	7 1/4" × 7 1/4"	1 triangles (cut twice on the diagonal)
Accent	1 square	7 1/4" × 7 1/4"	1 triangles (cut twice on the diagonal)

Fabric	Cut	Size	Then
Main	1 square	8 7/8" × 8 7/8"	1 triangles (cut once on the diagonal)
Background	1 square	9 1/4" × 9 1/4"	1 triangles (cut twice on the diagonal)
Accent	1 square	9 1/4" × 9 1/4"	1 triangles (cut twice on the diagonal)

Fabric	Cut	Size	Then
Main	1 square	12 7/8" × 12 7/8"	1 triangles (cut once on the diagonal)
Background	1 square	13 1/4" × 13 1/4"	1 triangles (cut twice on the diagonal)
Accent	1 square	13 1/4" × 13 1/4"	1 triangles (cut twice on the diagonal)

Cut the pieces in the chart above. All measurements include a 1/4" seam allowance.
Cut the squares marked "cut twice" on both diagonals. Each gives four triangles with the long edge on the straight grain: these are the large triangles in flying geese and hourglass units.
Cut the squares marked "cut once" in half on the diagonal. Each gives two triangles. Sew them to their neighbours along the long edge first and press toward the darker fabric.
Lay the pieces out as in the diagram and sew them together, matching the center.
The block should measure 12 1/2" now and 12" once it is sewn into the quilt.

Quilt size	Blocks	Finished size	Main	Background	Accent	Border & binding	Backing
Baby	3 × 4 (12)	42" × 54"	7/8 yd	1/2 yd	1/2 yd	1 yd	3 1/2 yd
Lap	4 × 5 (20)	54" × 66"	1 5/8 yd	7/8 yd	7/8 yd	1 1/8 yd	4 1/4 yd
Throw	5 × 6 (30)	66" × 78"	2 yd	1 1/4 yd	1 1/4 yd	1 3/8 yd	5 yd
Twin	6 × 8 (48)	78" × 102"	3 1/4 yd	1 5/8 yd	1 5/8 yd	1 3/4 yd	9 1/4 yd
Queen	8 × 8 (64)	102" × 102"	4 3/8 yd	2 1/2 yd	2 1/2 yd	1 7/8 yd	9 1/4 yd
King	9 × 9 (81)	114" × 114"	5 5/8 yd	2 7/8 yd	2 7/8 yd	2 1/8 yd	10 1/4 yd

Blocks side by side with a 3" border, 2 1/2" binding, 42" usable width and 10% extra.

A throw quilt of 12" Split Quarter-Square Triangle blocks in each setting.

Setting	Blocks	Finished size	Extra fabric
Side by side	30	66" × 78"	–
With sashing	20	60" × 74"	Sashing 7/8 yd, Cornerstones 1/8 yd
Alternating plain blocks	15 pieced + 15 plain	66" × 78"	Plain blocks 2 yd
On point	18	57" × 74"	Setting triangles 1 1/2 yd

1. Your fabrics (tap a fabric, then choose a sample or your own photo)

2. Block

3. Quilt size

4. Block size

5. Setting

Border

Fabric	Yardage	Cut

Based on 42" usable fabric width, 1/4" seams and 10% extra. Your photos stay on your device.

How many fabrics does a Split Quarter-Square Triangle block need?

Three: main, background and accent. Choose a main fabric that contrasts clearly with the background so the design reads from a distance.

What size pieces do I cut for a 12 inch Split Quarter-Square Triangle?

1 main square at 12 7/8" × 12 7/8"; 1 background square at 13 1/4" × 13 1/4"; 1 accent square at 13 1/4" × 13 1/4".

How many Split Quarter-Square Triangle blocks for a lap quilt?

20 blocks at 12", set 4 by 5 with a 3" border, make a 54" × 66" quilt.

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