Hourglass quilt block
Four quarter-square triangles meeting at the centre — two light, two dark, forming an hourglass on its side or upright depending on how you turn it.
Also known as Quarter-Square Triangle, Broken Dishes (regional).
The hourglass unit is the quarter-square triangle in its purest form, and like flying geese it is a component as much as a block. Its advantage over the half-square triangle is grain: cutting a square twice on the diagonal puts the straight grain on the unit's outer edges, so the block edge does not stretch.
Hourglass cutting chart
Cut sizes include a ¼″ seam allowance: ½″ on squares and rectangles, ⅞″ on half-square triangles, and 1¼″ on quarter-square triangles. Pick a finished block size:
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | QST square | 4¼" × 4¼" | 2 | cut twice on the diagonal → 8 triangles |
| Dark | QST square | 4¼" × 4¼" | 2 | cut twice on the diagonal → 8 triangles |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | QST square | 5¾" × 5¾" | 2 | cut twice on the diagonal → 8 triangles |
| Dark | QST square | 5¾" × 5¾" | 2 | cut twice on the diagonal → 8 triangles |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | QST square | 6¼" × 6¼" | 2 | cut twice on the diagonal → 8 triangles |
| Dark | QST square | 6¼" × 6¼" | 2 | cut twice on the diagonal → 8 triangles |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | QST square | 7¼" × 7¼" | 2 | cut twice on the diagonal → 8 triangles |
| Dark | QST square | 7¼" × 7¼" | 2 | cut twice on the diagonal → 8 triangles |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | QST square | 8¾" × 8¾" | 2 | cut twice on the diagonal → 8 triangles |
| Dark | QST square | 8¾" × 8¾" | 2 | cut twice on the diagonal → 8 triangles |
How it goes together
Two squares, each cut twice on the diagonal, recombined so opposite triangles match. Or make two oversized HSTs, cross them, and cut again — the faster route to the same unit.
Tips
- Cut squares 1¼ inches larger than the finished unit size.
- All four bias seams meet at the centre — press the final seam open to keep it flat.
- Chain a whole quilt's worth at once; hourglasses are almost never used singly.
How much fabric for a Hourglass quilt?
Yardage for a whole quilt of Hourglass blocks, computed the way the studio does it — every piece packed across a 40″ usable width with 10% added for waste.
| Quilt size | Blocks | Finished | Top fabric | Backing | Binding |
|---|---|---|---|---|---|
| Baby 36×48 | 12 | 36" × 48" | Background 1⅛ yd · Dark 1⅛ yd | 2½ yd | ⅜ yd |
| Throw 60×72 | 30 | 60" × 72" | Background 2¾ yd · Dark 2¾ yd | 3⅞ yd | ½ yd |
| Queen 90×108 | 72 | 96" × 108" | Background 6½ yd · Dark 6½ yd | 8¾ yd | ⅞ yd |
What it looks like in a quilt
A single block only tells you half the story. Set sixteen of them together and the secondary pattern appears where the blocks touch:
Hourglass questions
What is the difference between an hourglass and a half-square triangle?
An HST is one square split once diagonally into two triangles. An hourglass is a square split twice, giving four triangles, with the straight grain on the outer edge instead of the diagonal.
What size square for a 6 inch finished hourglass?
Cut squares at 7¼ inches — the finished size plus 1¼ inches.