Half Square Triangles, or HSTs for short, are one of the most versatile quilt blocks to make. Not only are they commonly found as smaller units within a block, but you can make an entire quilt out of nothing but half square triangles, in several different layouts.
HSTs are fairly straight forward when it comes to construction, and like many blocks in quilting, can be made several different ways. Before you learn how to make them, it’s important to know the difference between a ‘finished’ measurement and an ‘unfinished’ measurement, as these terms are used when determining what size of fabric square to start with in order to make the desired size of half square triangle. A ‘finished’ measurement refers to what size the block will be once it is sewn into a quilt. An ‘unfinished’ measurement refers to what size the block is before it is sewn into a quilt- meaning that it takes into account the ¼” seam allowance.
The first, and probably most common way to make an HST is to start with two squares of contrasting colored fabric. On the wrong side of one of the fabrics, draw a diagonal line from corner to corner. Align your fabric squares with right sides together and pin. Stitch ¼” on either side of the drawn line and then cut apart on the line.
Open up the half square triangles and press. This method will yield two half square triangles at one time. If you are wanting to make a specific size of HST, the way to figure out what size square to start with is to add 7/8”. For example, if you want to make an HST that finishes at 3”, you would start with two 3 7/8” squares.
If you are making an entire quilt from nothing by HSTs, or are just wanting to make more of them at a time, you can use an alternative method that allows you to make eight half square triangles at one time. Begin with two contrasting colored fabric squares. On the wrong side of one of the fabrics, draw two diagonal lines from corner to corner. Align the fabric squares with right sides together and pin. Stitch ¼” on either side of the drawn lines. Cut apart along the center vertically and horizontally and then along each of the drawn lines.
Open up the half square triangles and press. If you are wanting to make a specific size of HST, begin with the finished HST size. To that size, add 7/8” and then multiply by 2. For example, if you want to make HSTs that finish at 3”, you would start with two 7 ¾” squares. ((3 +7/8) x2). If your math does not yield an easy measurement, you can always round up to make slightly larger HSTs and then square your HST down to the correct size once it is pressed open.
Now you can try out these fun blocks to practice your HST skills:
Pinwheel and Broken Dishes
Make four HSTs and lay them out as shown. Sew together into two rows of two, and then sew the rows together.
Both Pinwheel blocks and Broken Dishes Blocks are made from the same number of HSTs, the only difference is how you lay them out.
If you want to make a lot of HSTs and put them together into a quilt, try out any of these fun layouts. All are made from HSTs in two colors- the only difference is how they are arranged. Simply layout the blocks as shown, sew together into rows and then sew the rows together. We’ve compiled 9 different layout ideas, for you, but the possibilities are endless! Make sure to show us what you come up within our National Quilters Circle Community Gallery!
- Layout Option 1
- Layout Option 2
- Layout Option 3
- Layout Option 4
- Layout Option 5
- Layout Option 6
- Layout Option 7
- Layout Option 8
- Layout Option 9
Thank you for the math formula to make any finished size!!! A big help.
What is a QST ? How do you make them? Thanks I understand if you can’t help here.
I would like to encourage quilters to measure and “square up” the HST before using for a block. I’ve found that no matter which method I use squaring up is needed.
Thank you for sharing your wonderful instructions!!
I enjoyed seeing how to make 8 HSTs at one time. I’m thinking using a 10″ precut square would make HSTs with finished size slightly smaller than 4.5″. Is there a formula to calculate this?
Hello Mary,
Thank you for contacting us.
I have just emailed you a chart for a variety of size squares and the outcome sizes for 8 at a Time HST.
If you have any other questions, please chat, email, or call Customer Service.
Sincerely,
Sarah
National Quilters Circle Video Membership
Is it possible to get a copy of the various sizes to start and finish HST’s?
Thank you
Linda John
lindajoj2008@gmail.com
Hi Linda. Thanks for contacting the National Quilters Circle with your question. Having a chart makes life easy. I am sending you the link to a video event where I taught a project called Sapphire Shimmer. A simple copy and paste of the address will take you directly to the project. It is an event where I taught both of the techniques Ashley covered in her article. The link to the pattern is in the description and the pattern includes charts for both making HST 2@aTime and 8@aTime method in a variety of sizes. Note: this method allows for a quick trim for perfect patchwork. If you wish to bypass the trim, the document gives directions to omit this step if you prefer. I hope you find this helpful and inspires new quilt projects.
Sapphire Shimmer
https://www.nationalquilterscircle.com/video/nqc-live-may-2022/
Happy Quilting
Colleen
National Quilters Circle
Thank you so much. I’m new to quilting and this guide for the layout is just what I needed. God bless u.
Hello Annie,
Thank you for your feedback. I have forwarded your comment to the proper department. We value your opinion, and it will help with the development of our online streaming community. We will continue to listen and work hard for your complete satisfaction.
Sincerely,
Sarah
National Quilters Circle Video Membership
Thank you for the HST ideas ,they look great. I am really looking forward to my quilting year!
Love all the ideas!
I tried this method but having problem making the points meet at the Center like above picture. What am I doing wrong? Thank you.
Hello Virginia,
Here’s what the experts had to say about your question:
Ensure that you are measuring and drawing your initial vertical and horizontal line directly in the center of each side. If you do this from the beginning, the points will match in the center when cut apart.
Cheers,
Ashley
Sincerely,
Danesha
National Quilters Circle Video Membership
Are layout options 1-3 the same? 4-6 the same and 6-9 the same?? Really three options with multiple copies??
Hello Jan,
Here’s what the experts had to say about your question:
Perhaps ‘layout option’ was the wrong way to word these. They are simply steps to show how to lay out the pieces, how to assemble into rows and then what it looks like all together.
Cheers,
Ashley
Sincerely,
Danesha
National Quilters Circle Video Membership
I was a member for a year and NEVER received any information from you. Now that my membership expired, I get emails all the time… What gives??
Hi Kathleen. If you would prefer not to receive any emails please email us at nationalquilterscircle@program-director.net requesting to unsubscribe and we would be happy to take care of this for you. I am sorry for any inconvenience.
Jean
National Quilters Circle Video Membership
I’m loving the quilting stuff. Amazing!!!!
When cutting QSTs how much do you add to the basic block when cutting?
Hello Adrian,
Thank you for contacting us.
For cutting QSTs, add 1 1/4″ to the finished size you want the QSTs to finish at (when sewn together). Meaning that if you want a finished unit made from 4 QSTs to measure 3″, you would cut the pieces from a starting square of 4 1/4″.
If you have any other concerns, please contact us at 1-855-706-3538, or chat with us on our site.
We greatly appreciate your business!
Sincerely,
Lindsay
National Quilters Circle Video Membership
This was GREAT. thank you
i am just learning so need all the help available. i can not work for health resons so have time. thank you happy new year.
This is my 1st read here and I know I’m going to be “sew” glad I subscribed! I got a better understanding of Hat’s than I have in watching all the tutorials I have viewed over the last 2 months as a born again quilter, meaning I learned to quilt from my Grannie in my early 20’s. Then life happened, now at 60, I have picked back up the art and am addicted already.
Thank You for a Great Guide I would love to get a Pdf of the ½ Square Triangle Instructions and Pictures as Well that would be Fantastic As Well as the Other PDFs Cheers Kylie 😁
I love Half-Square Triangle paper. Many sizes are available. Very easy to use.
Just love the new things I’m learning how to do.
Are there instructions that i can purchase for each of the layout options given here?
Hello Martha,
Thank you for contacting us. I’m sorry but there are no printed instructions to purchase, but you can print these out for yourself to keep in
If you have any other concerns, please contact us at 1-855-706-3538, or chat with us on our site.
We greatly appreciate your business!
Sincerely,
Joan
National Quilters Circle Video Membership