SeeMyQuilt12 inch Split Quarter-Square Triangle quilt block
Cutting chart, piecing steps and yardage for a Split Quarter-Square Triangle block that finishes at 12". The block is a 1 × 1 grid and each cell finishes at 12".
Cutting chart for one block
| 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) |
How to piece it
- 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.
Yardage for a quilt of 12" Split Quarter-Square Triangle blocks
| 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.
What a lap quilt looks like
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
What to buy
| Fabric | Yardage | Cut |
|---|
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 12 inch Split Quarter-Square Triangle block?
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".
What size is the block before it is sewn into the quilt?
12 1/2" square. It finishes at 12" once the seams on all four sides are sewn.
How much fabric for a throw quilt of 12 inch Split Quarter-Square Triangle blocks?
30 blocks make a 66" × 78" quilt. Buy 2 yd of main, 1 1/4 yd of background, 1 1/4 yd of accent and 1 3/8 yd of border & binding, plus 5 yd for the backing.
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