On-Point Layout Calculator
Zero Waste & No Sign-up: Calculate setting triangles and corner triangles for on-point quilt layouts. Get exact cutting sizes to achieve perfectly flat edges when blocks are set diagonally.
How to Use the On-Point Calculator
Enter your finished block size and the number of blocks across and down. Set on point, each block stands on its corner, so the layout spans the block's diagonal — 1.414 times its side — and the calculator reports the approximate finished quilt dimensions on that basis.
Side setting triangles come from squares cut at the block size times 1.414 plus 1-1/4 inches, each cut on both diagonals into four triangles. Corner triangles come from squares cut at the block size divided by 1.414 plus 7/8 inch, cut once diagonally into two. These formulas keep the straight grain on the quilt's outer edges.
The tool counts the pieces for you: side triangles total two times the sum of blocks across and blocks down, minus two of each — so a 3 x 4 layout needs ten side triangles, which is three squares' worth, plus the four corner triangles that always come from two corner squares.
Frequently Asked Questions
What does 'on point' mean in quilting?
Setting blocks 'on point' means rotating them 45 degrees so they sit diagonally. This creates a dynamic design where the blocks appear to float, and requires setting triangles to fill the edges.
How do I calculate setting triangle sizes?
For side setting triangles, multiply the finished block size by 1.414 and add 1.25 inches. For corner triangles, divide the block size by 1.414 and add 0.875 inch. Our calculator does this automatically.
Why do on-point quilts need corner triangles?
Corner triangles fill the four corners of the quilt top when blocks are set diagonally. Without them, the corners would be incomplete and the quilt would not have straight edges.