How to Make 8 at a time Half Square Triangles

Jan 24, 2023
2 min read

Updated: Aug 11, 2025

Do you shy away from making half square triangles? I used to. Now that I've learned how to make 8 at a time half square triangles (HSTs), I'm calling that my new quilting superpower.

With just a few basic tools, it's easy to turn a few squares of fabric into beautiful half square triangles, making for a fun and creative journey for any level of quilter.

Introduction to the 8-at-a-Time Method

Today, I'm going to show you how to make 3 1/2" HSTs. Rather than making them 1 at a time, we're using two 9" squares of fabric to make 8 of them. It's easy and fast!

What You’ll Need

Washable fabric marking pen

Scissors or rotary cutter

Sewing machine

Thread

(2) 9" squares of fabric

Step-by-Step: 8 at a Time Half Square Triangles

Marking the Fabric for 8 at a Time Half Square Triangles:

You will need to mark your own lines, of course, but I have already marked mine in the photographs. You'll notice they are blue. I've added the ruler to show where you need to mark your lines.

Mark the diagonal lines

Using washable marking pen, mark 2 diagonal lines on the wrong side of one of the squares. See photos below.

Fabric square on a black cutting mat with blue washable pen and quilting ruler, showing how to mark the first diagonal line for half square triangles — **Marking the diagonal line - 1**

Marking the second diagonal line on a fabric square for 8 at a time half square triangles, using a quilting ruler and blue washable pen on a cutting mat — **Marking the diagonal line - 2**

Mark a horizontal line

Using washable marking pen, mark 1 horizontal line across the wrong side of the same fabric square. See photo below.

Mark a vertical line

Now, mark a vertical line going from top to bottom on the wrong side of the same square See photo below.

You should now have 4 lines drawn on the wrong side of the same fabric square just as I do.

Stitching Along the Diagonals

Put both fabric squares right sides together (RST) with the marked piece on the top side where you can see the lines you drew. Sew 1/4" from the diagonal lines on both sides of the line.

You should now have 4 lines of stitching. See the close-up photo below.

Close-up of fabric square showing stitching lines on both sides of each diagonal, as part of the 8 at a time half square triangles sewing method — **Notice the seam lines on either side of the blue diagonal lines only.**

Cutting the Square into Triangles

Using scissors or a rotary cutter, carefully cut along all of the blue lines you drew. You should now have 8 pieces. See photo below.

Fabric square cut into 8 triangles using a rotary cutter along the marked blue lines, part of the 8 at a time half square triangles method — **Cut on blue lines ONLY**

Pressing and Trimming the Half Square Triangles

Press

Press to set seam. Now, open the half square triangle and press seam to one side, or press seam open, if preferred. If you press to one side, it is easier to nest seams later.

Trim

Now that you have pressed all the half square triangles, trim to desired size. For this tutorial, you should trim to 3 1/2" x 3 1/2".

Voila!

Stack of untrimmed half square triangles next to two stacks of pressed and trimmed units, with rotary cutter and clear quilting ruler on a black cutting mat — **Pressed and Trimmed HST's**

Now you have a quilting superpower just like me.

What next?

Now that you’ve mastered 8 at a time half square triangles, put your new skills to use!

My Patches of Friendship pattern uses this exact method and is perfect for your next project. Buy the pattern here.