Magic 8 HST

This is a method in which you cut two squares of fabric to obtain 8 half-square triangles (HST). Place the squares right sides facing, and stitch 1/4″ on either side of a line drawn on each diagonal, that is, from corner to corner. After stitching and without moving the fabric, cut the square in half horizontally and vertically then cut diagonally between the stitching. Presto! Just like magic you have 8 HST for only 4 rows of stitching.

Cut the exact size squares if your stitching is usually perfect. Cut the larger to trim size if, like me, your stitching isn’t always perfect. This will give you slightly oversized HST which can then be trimmed to a perfect size. The formula is as follows:

Start with the finished size of your HST. Add 7/8″ to this. Multiply this number by 2 and cut two squares that size. If you want to make your HST larger and then trim them down, add 1″ instead of 7/8″

You can download a PDF of these calculations for finished sizes from

You can use the chart below or download it as a PDF.

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