Lone Star Calculator
The eight-point star at quilt scale, every point pieced from a grid of small diamonds. Pick how many diamonds per point and your strip width, get the block size, every strip set in order, and the background cuts, then follow the construction from strip set to finished star.
Pick diamonds per point (4 × 4 is the classic) and type your strip width; 2½″ is a jelly roll. The block size fills itself in. The cut list shows each strip set with its fabrics in order, how many strips of each ring, and the two background cuts. Then follow the pictures: four steps make the points, the rest sets them together.
What a Lone Star actually is
A LeMoyne Star whose eight diamonds are each pieced from a grid of smaller 45° diamonds. Colour the small diamonds by how far they sit from the center and you get the concentric rings the block is famous for; colour them by column and you get radiating lines; use a different fabric in every one and it is scrappy. Whatever the colouring, the geometry is the same, and so is the shortcut: every row of a point is a strip set cut at 45°, so a whole quilt center is a handful of strip sets, some subcutting, and eight Y-seams.
Making a single block instead? The LeMoyne Star calculator is the same star with one diamond per point, and there you choose the block size and the strip follows.
Questions people ask
Why do I type a strip width instead of a quilt size?
Because the strip is what you cut. A strip W wide at a ¼″ seam makes a diamond (W − ½″) × √2 on a side; a point is N of those; the block is (2 + √2) times the point. Go the other way, from a quilt size to a strip, and you get a strip like 2.379″ that no ruler has. The By block switch shows you that number so you can see why, then nudges you to the nearest strip you can actually cut.
2½″ strips at 4 × 4 makes a 38.6″ star. Can I get 36″?
Only with a 2.37″ strip, which you can’t cut. Real Lone Star patterns solve this the other way round: they take the star the strips make and fit the quilt to it with borders. TideStitch does the same; its border tools fit a top around whatever the center measures.
What is a strip set, and why are there N of them?
Each point is an N × N grid of small diamonds coloured in rings from the center out. Look along one direction and every row of N diamonds is a run of N fabrics; sew those N strips together and cut the set at 45° and you get that row, eight times over. The rings shift by one fabric each row, so row 1 is rings 1 to N, row 2 is rings 2 to N + 1, and so on: N different sets.
Why offset the segments by ¼″ when I join them?
Because the small diamonds meet at their points, not their sides. Two segments laid raw edge to raw edge with the seams lined up would put every diamond a quarter inch off; offsetting them by exactly one seam allowance makes the seam lines cross ¼″ in from the edge, which is where the sewn point lands. Pin straight through each crossing before you sew.
Why measure a point before cutting the background?
Because N seams across a point drift more than one seam does, and the corner squares have to match the point’s edge exactly or the star won’t lie flat. The calculator gives you the number the point should measure; if yours came out a hair different, cut the squares and triangles to what you actually have. Every good Lone Star pattern says this, and it is the single best piece of advice in this whole page.
Is the math the same as in TideStitch?
Yes. The app makes a Lone Star from the same recipe (diamonds per point, strip width or block size), names its diamonds as strip cuts and its background as squares and quarter-square triangles at whatever seam you set, and figures the background from the sewn point. This page assumes ¼″. In the app you also paint the rings from your own stash and get the cut list per fabric.