6 Steps to Easy Half-Square Triangles

Half-square triangle units (also known as HSTs) can be daunting for a beginning quilter, but once you get the hang of it, you’ll be making them all the time from your stash scraps.  Pieced together, they make some very beautiful patchwork quilts; you’ll love rotating them around until you find the exact look you want.

So what are HSTs?  They’re fabric squares made up of two 90 degree triangles.  But don’t get ahead of this lesson by cutting two triangles and sewing them together…there’s a much easier way to get perfect half-square triangles.

  • Put two fabric squares together, right sides facing each other
  • Draw a diagonal line from either upper corner to the opposite lower corner
  • Sew a 1/4″ seam along both sides of your pencil diagonal line
  • Cut the square on the diagonal line (rotary is faster)
  • Finger press your seam open then lightly touch it with the iron
  • Trim dog ears

And voila!  You’ve just sewn a perfect half-square triangle.

Here’s a visual tutorial from Janet Wickell at The Spruce to help you see the steps.

Don’t you just LOVE that HST patchwork design in the photo?  It’s from Debbie Moyes from A Daily Dose of Fiber.  Check it out!