Windmill Eight quilt block
A square cut by both diagonals and both midlines into eight identical right triangles. Alternate them light and dark and it turns like a windmill.
Also known as Windmill, Eight-wedge pinwheel, Kaleidoscope square.
This is the simplest of all eight-wedge drafts and one of the oldest, because it needs nothing but half-square triangles: each of the eight pieces is half of a small square cut once on the diagonal. Quilters have used it under many names, most of them involving wind or water, and it turns up constantly as the centre of larger blocks.
Windmill Eight 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 | HST square | 3⅞" × 3⅞" | 2 | cut once on the diagonal → 4 triangles |
| Dark | HST square | 3⅞" × 3⅞" | 2 | cut once on the diagonal → 4 triangles |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 5⅜" × 5⅜" | 2 | cut once on the diagonal → 4 triangles |
| Dark | HST square | 5⅜" × 5⅜" | 2 | cut once on the diagonal → 4 triangles |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 5⅞" × 5⅞" | 2 | cut once on the diagonal → 4 triangles |
| Dark | HST square | 5⅞" × 5⅞" | 2 | cut once on the diagonal → 4 triangles |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 6⅞" × 6⅞" | 2 | cut once on the diagonal → 4 triangles |
| Dark | HST square | 6⅞" × 6⅞" | 2 | cut once on the diagonal → 4 triangles |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 8⅜" × 8⅜" | 2 | cut once on the diagonal → 4 triangles |
| Dark | HST square | 8⅜" × 8⅜" | 2 | cut once on the diagonal → 4 triangles |
How it goes together
Eight right triangles, each half of a square whose finished leg is half the block. Sew into four squares, then join those into a four patch — no set-in seams and no templates.
Tips
- It is really four half-square triangles in a four patch, so use whichever HST method you already trust and skip the templates entirely.
- Press the four quarter-square seams in a circle so the centre spins flat rather than stacking.
- This block is a good place for a directional print: rotating the same fabric eight ways makes it look like eight different fabrics.
How much fabric for a Windmill Eight quilt?
Yardage for a whole quilt of Windmill Eight 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 2⅝ yd · Dark 2⅝ yd | 3⅞ yd | ½ yd |
| Queen 90×108 | 72 | 96" × 108" | Background 6⅛ yd · Dark 6⅛ 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:
Windmill Eight questions
How is this different from the Kaleidoscope block?
Kaleidoscope divides an octagon into eight equal wedges and fills the square’s corners separately, so its wedges need a template. This one just cuts the square on both diagonals and both midlines, so every piece is an ordinary half-square triangle.
What size squares do I cut?
The eight triangles come from four squares whose finished size is half the block. For a 12 inch block that is 6 inches finished, so cut four 6⅞ inch squares and cut each once on the diagonal.