SeeMyQuilt
Pinwheels & triangles · Confident beginner · 4" finished

4 inch Split Quarter-Square Triangle quilt block

Cutting chart, piecing steps and yardage for a Split Quarter-Square Triangle block that finishes at 4". The block is a 1 × 1 grid and each cell finishes at 4".

Finished block 4" × 4". Unfinished 4 1/2" × 4 1/2".

Cutting chart for one block

FabricCutSizeThen
Main1 square4 7/8" × 4 7/8"1 triangles (cut once on the diagonal)
Background1 square5 1/4" × 5 1/4"1 triangles (cut twice on the diagonal)
Accent1 square5 1/4" × 5 1/4"1 triangles (cut twice on the diagonal)

How to piece it

  1. Cut the pieces in the chart above. All measurements include a 1/4" seam allowance.
  2. 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.
  3. 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.
  4. Lay the pieces out as in the diagram and sew them together, matching the center.
  5. The block should measure 4 1/2" now and 4" once it is sewn into the quilt.

Yardage for a quilt of 4" Split Quarter-Square Triangle blocks

Quilt sizeBlocksFinished sizeMainBackgroundAccentBorder & bindingBacking
Baby8 × 11 (88)38" × 50"1 yd1/2 yd1/2 yd1 yd3 1/4 yd
Lap11 × 14 (154)50" × 62"1 1/2 yd7/8 yd7/8 yd1 1/8 yd4 yd
Throw14 × 17 (238)62" × 74"2 1/4 yd1 3/8 yd1 3/8 yd1 3/8 yd4 3/4 yd
Twin17 × 23 (391)74" × 98"3 3/4 yd2 1/8 yd2 1/8 yd1 3/4 yd6 yd
Queen23 × 23 (529)98" × 98"5 1/8 yd2 3/4 yd2 3/4 yd1 7/8 yd9 yd
King26 × 26 (676)110" × 110"6 1/2 yd3 5/8 yd3 5/8 yd2 1/8 yd10 yd

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

What a lap quilt looks like

11 × 14 blocks, 50" × 62" with border.

This diagram uses plain colors. To see the quilt in your own fabrics, with sashing or on point, use the tool below: tap a fabric and choose a photo.

See it in your own fabrics

1. Your fabrics (tap a fabric, then choose a sample or your own photo)
2. Block
3. Quilt size
4. Block size
5. Setting

What to buy

FabricYardageCut

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

Questions

What do I cut for a 4 inch Split Quarter-Square Triangle block?

1 main square at 4 7/8" × 4 7/8"; 1 background square at 5 1/4" × 5 1/4"; 1 accent square at 5 1/4" × 5 1/4".

What size is the block before it is sewn into the quilt?

4 1/2" square. It finishes at 4" once the seams on all four sides are sewn.

How much fabric for a throw quilt of 4 inch Split Quarter-Square Triangle blocks?

238 blocks make a 62" × 74" quilt. Buy 2 1/4 yd of main, 1 3/8 yd of background, 1 3/8 yd of accent and 1 3/8 yd of border & binding, plus 4 3/4 yd for the backing.