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Square in a Square Calculator

Enter your finished block and get the center square and corner-triangle cuts — with the correct sqrt(2) math, not the rounded-up version that finishes too big.

Center square cut

In the app, this also gives you

  • Oversize-and-trim option
  • The formula, shown every time
  • Saved into your project's cut list

The economy block, without the extra inch

In a square-in-a-square block, the center square's diagonal becomes the block's width — so the center finishes at block ÷ √2, not block ÷ 2 + something. Cut it at that finished size plus two seam allowances. The corner triangles come from two squares cut at block ÷ 2 + 7/8", each cut once on the diagonal. Some calculators round these numbers up so far the block finishes a full size too large; this one uses the real geometry, with an oversize-and-trim option if you prefer insurance.

There's more where that came from

The app has every block unit with the formula shown, an oversize-and-trim option, and saves your calculations to the project they belong to.

Coming to the App Store for iPhone and iPad.