Block Basics: Half-Square Triangles – 2 at a Time

If you’re here to put together our Beginner Skill Builder Sampler Quilt, welcome! This is Month 1, Week 1, and I’m glad you’re here!

If your just here to learn how to do 2 at a time Half-Square Triangles, you’re in the right place too.

Half-square triangles (HST) are very versatile and simple, and a great way to start your quilting journey.

2-at-a-Time Half-Square Triangles

Cut List

  • 1- 4” x 4” background fabric
  • 1- 4” x 4” colored fabric

Draw a diagonal line in the lighter fabric from one corner to the opposite corner.

Sew 1/4″ down each side of the diagonal line.

Cut down diagonal line.

Press toward dark fabric.

Measure and Trim

We want to trim to 3 1/2” square.

When your done, you should have 2 half-square triangles (HST).


If you have any questions, please go watch the YouTube video. I go into much more detail in the video, and you can watch it and follow along.

If you have questions after that, drop them in my comment section below, or on the comment section of the video and I will come and answer them.

How to Make Any Size Block

What if you want a different size of your block? It’s time to do some math.

In order to do that, we need to figure out what size of starting square you’ll need.

Take the unfinished size of your HST, and add 1/2″. Yup! It’s that easy.

So if you want a 5 1/2″ unfinished HST, add 1/2″ to get 6″ and start with 2-6″ Squares.

Beginner Skill Builder Sampler Quilt

If you are sewing along with me and making Beginner Skill Builder Sampler Quilt you will need to make 4 half-square triangles. I made mine 2 of one color and 2 of another color (see below), but you are welcome to sew them with different colors.

Next week we’re going to learn how to make a Stitch-and-Flip Flying Geese.

Tag me!

I would love to see your progress. Just tag me at #theashleytomlinson or #ashley_sunnymade and I’ll be able to see you on social media. 

I would love to see how they turn out!

Happy sewing!