Skip to main content

Setting Triangles Calculator

For quilts set on point: enter your block size and get the squares to cut for side and corner triangles, with the grain running the right way.

Side triangle squares

In the app, this also gives you

  • A full on-point quilt plan
  • Sashing handled automatically
  • The whole cut list, exportable as PDF

Why setting triangles are cut from two different squares

On an on-point quilt the outer edges must sit on the straight grain, or they stretch. Side triangles come from a square cut block × 1.414 + 1 1/4", cut on bothdiagonals so each of the four triangles has its long edge on grain. Corner triangles come from a square cut block × 0.707 + 7/8", cut on one diagonal. If your layout has sashing, the triangles must span the block plus its sashing — this calculator handles that for you.

More on the geometry: block sizes and on-point settings.

There's more where that came from

The app designs the whole on-point quilt — blocks, sashing, setting triangles — and hands you the finished size and complete cut list.

Coming to the App Store for iPhone and iPad.