In this quilt block tutorial I am going to teach you exactly how to make easy Half Square Triangles using the most beginner-friendly method ever! I used this Half Square Triangle technique on my very first quilt and still use it today! This method of making HSTs is super popular and for good reason! I use the 2-at-a-time HST method in my upcoming Sail Quilt Pattern.
I’ve gotta tell you – there are many MANY ways to make Half Square Triangles, and this is just one method. I hope you will learn this one along with a few others such as 4-at-a-time or 8-at-a-time too!
You can learn how to make easy Half Square Triangle Quilt Blocks by reading the step-by-step instructions below, or by watching this quick video:
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Easy Half Square Triangle Math
One of the reasons this is the easiest way to make half square triangles is that the math is super simple! All you need to do is take the FINISHED HST size you want and add 1 inch. Cut 2 squares to that size and you can easily make 2 Half Square Triangle Quilt Blocks.
Finished vs. Unfinished Quilt Blocks
If you’re new to quilting you might not know what I mean by “FINISHED HST” – a finished quilt block is after it has been stitched to the other blocks, meaning it has lost the seam allowance, which is typically 1/4″ on all sides. This means that an unfinished quilt block is 1/2″ larger than a finished block.
Sewing 2 Squares into 2 HSTs
Here are the super simple steps to make 2 Half Square Triangles from 2 squares of fabric, once they are cut to size.
- Draw a diagonal line on the wrong side of 1 square. I use heat-erasing pens.
- Match up squares right sides together
- Sew on each side of the diagonal line, using a scant 1/4″ seam allowance
- Cut directly on the line.
- Press open or to the dark side.
- Trim to desired size.
Other Half Square Triangle Techniques
While the above tutorial shows the easiest way to make Half Square Triangles, you may consider one of these other methods if you need more than 2.
- 4 at a time Half Square Triangles
- Magic 8 Half Square Triangles
- Perfect Half Square Triangles with AccuQuilt