Jacquelynne Steves

Half Square Triangle (HST) Cheat Sheet and Tutorial

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If you’ve been quilting for more than 5 minutes, you’ve probably made a HST (Half Square Triangle unit) a time or two (or hundred or thousand.) There are actually several ways to make them, but today I thought I’d show you the most common way to do it. Just in case you’re not sure what I’m referring to, a HST looks like this, and we tend to use them A LOT in quilting:


Each square is cut in half into 2 triangles, and then sewn back together to form a square.

I really like to make my units a little big and then trim them down to the perfect size- I find that no matter how careful I am with cutting, pinning, and sewing, my units can end up a little wonky. (Some people use starch to make their units behave… which is a fine solution… I just don’t like to have to clean my iron.)

I’ve made up a PDF “Cheat Sheet” for you- it’s basically a guide so you can tell at a glance what size to cut your squares for making HSTs. PLEASE NOTE- I NOTICED AN ERROR IN MY ORIGINAL CHART- PLEASE MAKE SURE YOU HAVE THE ONE THAT SAYS “REVISED.” THANKS!



Let’s go over how to use the chart!

You can choose whether you want to make the HST the exact size you want it to be, or if you want to make it a little big so you can trim it down.

Look on the left side of the chart- the 2 yellow columns will show you the size of the HST when it’s done (I’ve given you measurements with and without seam allowance, because I know sometimes my brain doesn’t want to do that extra little bit of math, and I figure that some of you are the same way, LOL.) So let’s say you need your HST’s to be 5″ in your quilt- that means you need them to be 5 1/2″ with the seam allowance. Find that measurement in the chart:hstcheatsheet-diagram_corrected


Then just look to the right, and choose the measurement in the first white column if you are making them to the exact size. Choose the measurement in the second white column if you are making them larger for trimming. This is the measurement that you will cut the squares.



If you need an unusually sized HST (5 3/8″??  3 7/8″???), I’ve also included the FORMULA at the bottom of the chart for calculating what size squares to cut. (Sorry- you WILL have to do the math for this) I’ve included the formulas both for making the HSTs to the exact size needed and for making them a little big for trimming:



Now, let’s make some HSTs using the chart! Remember that however many squares you cut, that is now many HSTs you will end up with. So, if you cut 2 squares and sew them up according to this method, you will end up with 2 identical HSTs. If you cut 50 squares and assemble them according to this method, you will end up with 50 HSTs.

As I mentioned, I like to make mine a little big and trim them, so that’s how I’m going to make mine. Using the example above, I want my HSTs to be 5 1/2″ (so that their finished size in my quilt is 5″.) So, I’m going to cut 2 squares which are 6 1/8″.


On the WRONG side of the fabric, I will draw my line down the center diagonally, which will be my cutting line. Then I draw a line 1/4″ from the center line- these will be my sewing lines. (You can skip drawing those sewing lines if you want, and rely on your 1/4″ mark/guide on your machine. But I like having the lines there to insure accuracy.) I found this nifty little ruler which makes it really easy to draw your lines.


Pin 2 squares RIGHT SIDES TOGETHER. I will sew on the side lines, and then cut the center line:


I open them up and press- depending on the pattern, sometimes I press the seam open, and sometimes I press it to the darker fabric.


Now, if you chosen to make them to the exact size, you would just trim off those “dog ears,” and you’re done.


But since I’ve made mine a little big, the measurements in the chart have resulted in HSTs which are about 5 3/4″, so I’ll trim them to my desired 5 1/2″. A note about trimming the HSTs- be sure to use the 45 degree line on your cutting mat, or on your ruler. This will assure that you have PERFECT HSTs:


Now I have 2 pretty HSTs.


That’s it! Click here for a downloadable PDF of the cheat sheet, then print it out and put it next to your cutting table for easy reference!




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    Posted June 22, 2016 at 11:15 am | Permalink

    Love all your designs and easy instructions! Thank you!

    • Janice
      Posted December 26, 2017 at 9:51 pm | Permalink

      This is a great chart! You have no idea how much it has helped. Thanks so very much!

  • Joyce Carter
    Posted June 22, 2016 at 2:55 pm | Permalink

    Thank you so much. I have been cutting HST’s for the past two weeks and my brain is tired from trying to figure out how big I need to cut the squares. You have saved me a lot of time and trouble. I really appreciate this.

  • Margaret (margiestitcher)
    Posted June 23, 2016 at 3:08 am | Permalink

    many thanks downloaded and will be printed later today

  • Sue Hook
    Posted June 23, 2016 at 9:36 am | Permalink

    This is great! Thanks so much

  • Lori Smanski
    Posted June 23, 2016 at 9:41 am | Permalink

    this is wonderful. thanks. but my computer/printer says that this document can not be printed. something about a drawing error.

    • Jacquelynne
      Posted June 23, 2016 at 9:49 am | Permalink

      Hi Lori- do you have the latest version of Adobe? I’ve tested it here and it prints ok for me.

  • Adela
    Posted June 23, 2016 at 2:06 pm | Permalink

    I am unable to print this sheet, here or on your craftsy page>>>

    • Jacquelynne
      Posted June 23, 2016 at 2:47 pm | Permalink

      Hi Adela- I’ve tested it here a couple of times and it downloads and prints OK for me. I re-uploaded the file to see if that helps. Please make sure that you have the most recent version of Adobe and try again.

    • LadyD
      Posted July 28, 2017 at 6:24 pm | Permalink

      Besides having the latest Adobe software, you might try printing just after you restart your computer. I don’t know all the details behind why restarting the computer works, but it does for me.

  • Diana (Nanna Ray)
    Posted June 23, 2016 at 6:20 pm | Permalink

    Thanks for the cheat sheet Jacqueline. I always use this method for HSTs using that nifty ruler to mark the lines but have never thought of making the squares larger then cutting down to size until I made the HSTs for Block One in ‘Maggies First Dance’ . My squares have turned out perfect!

  • Gay Ferland
    Posted June 23, 2016 at 6:32 pm | Permalink

    I could not get this to print. Wonder if I am the only one who can’t print it off? My adobe is up to date.
    Help please.

    • LadyD
      Posted July 28, 2017 at 6:27 pm | Permalink

      If you have not restarted your computer recently that might be why you cannot print the HST chart.

  • Teresa
    Posted June 24, 2016 at 10:35 am | Permalink

    Thanks very much, a really useful chart to have by you.

  • Anne Jacobs
    Posted June 24, 2016 at 5:16 pm | Permalink

    I will look forward to your posts!

  • Margo Baker
    Posted June 27, 2016 at 8:35 am | Permalink

    Thank you so much for this cheat sheet.

  • Anita Jackson
    Posted June 27, 2016 at 4:19 pm | Permalink

    Oh! The ruler! It looks like Fons&Porter? Not sure. Do you remember the name of the ruler and where to purchase?

  • Lesley Gilbert
    Posted June 27, 2016 at 5:31 pm | Permalink

    Thanks for the cheat sheet – thinking of you and your family x

  • Patricia Cash
    Posted June 27, 2016 at 5:32 pm | Permalink

    Thank you for the sheet and tutorial.

  • Rosie
    Posted June 27, 2016 at 5:55 pm | Permalink

    Your explanations are so easy to follow and are very educational. You make it so easy to understand that I can’t fail when making HST’s now. Thanks.

  • Clairequilty
    Posted June 27, 2016 at 6:13 pm | Permalink

    This chart came at the perfect time for me because of the project I am starting today. Thank you. Often I think of the words at the bottom of this page. It has made quite a difference (all good) in my life. May Peace be with you.

  • Roxanne Hartwig
    Posted June 27, 2016 at 6:28 pm | Permalink

    Thank you Jacqueline – this chart is wonderful! Our prayers are with you and your family.

  • Kathleen
    Posted June 27, 2016 at 7:51 pm | Permalink

    Oh thank you for this! This will come in real handy!

  • Rita
    Posted June 27, 2016 at 8:20 pm | Permalink

    Thanks so much for cheat sheet, downloaded,printed,and posted by cutting table.Prayers and thoughts for you and your family.

  • Anonymous
    Posted June 27, 2016 at 9:35 pm | Permalink

    My prayers will include you and your family! Thank you for the HST. Will definitely use that method from now on.

  • JulieG-AZ
    Posted June 27, 2016 at 9:57 pm | Permalink

    Thank you for the HST cheat sheet. I need to print and post somewhere that I won’t forget I have it!

  • Shirley Lambeth
    Posted June 27, 2016 at 10:29 pm | Permalink

    Thank you for the HST tutorial. Thoughts and prayers are with you and your family.

  • Kaye Walker
    Posted June 27, 2016 at 10:45 pm | Permalink

    Thank you for this cheat sheet. It will be very helpful.

  • Pam Foster
    Posted June 28, 2016 at 12:03 am | Permalink

    Thank you so much for this tutorial so handy. Thoughts are with you and your family at this time.

  • Janan
    Posted June 28, 2016 at 12:05 pm | Permalink

    Stitch therapy and friend therapy! Sending you hugs and prayers.
    Thank you so much for the HST sheets and charts! These will be so useful.

  • sandy Lowery
    Posted June 28, 2016 at 12:23 pm | Permalink

    Thanks for this chart, it will be very handy.

  • Marcia
    Posted July 22, 2016 at 8:41 am | Permalink

    Thank you for your wonderful instructions & cheat sheet. It makes everything so much easier.

  • K A Leach
    Posted August 7, 2016 at 7:25 am | Permalink

    Is there a sheet for Quarter Square triangles?

  • juliana
    Posted September 24, 2016 at 1:44 am | Permalink

    Thank you soooo much for the cheet sheet. Have printed and laminated the sheet. Thanks for the work put into working out the formulas. Makes my life easier when making quilts. Love your site/blog.

  • Posted October 5, 2016 at 11:49 pm | Permalink

    Question might be silly: 1/4 inch seam marked on the HST should they be scant 1/4 inch or full 1/4 inch?

  • Sally
    Posted October 15, 2016 at 12:56 pm | Permalink

    Thank you for doing this revision. I have it printed out and will replace the previous one. I love your creativity and your projects!

  • Annita Cormack
    Posted May 13, 2017 at 11:58 am | Permalink


  • Posted July 19, 2017 at 11:21 am | Permalink

    This is super helpful! I am trying to make a modern sampler quilt and am re-sizing blocks and you just saved me hours of math! Very much appreciated.

  • Daisy
    Posted July 29, 2017 at 3:16 am | Permalink

    Thank you Jacquelynne for the information. Really appreciate it. Looking forward to the start of the new quilt.

  • Tammy
    Posted August 15, 2017 at 4:44 pm | Permalink

    Will the chart print from an iPad?

  • Tammy
    Posted August 17, 2017 at 10:08 am | Permalink

    I found the download link under the last photo! Thanks!

  • Irene
    Posted September 24, 2017 at 7:36 pm | Permalink

    Thank you! thank you! thank you! I just spent a few hours trying to get the right measurements and it was right here all the time. bless you

  • Joanna Perry
    Posted September 26, 2017 at 6:36 pm | Permalink

    Thank you. Great help.

  • LaTawnia Porter
    Posted January 15, 2018 at 12:14 am | Permalink

    Thank you, thank you! Finally a HST chart that makes sense! I am doing more of these fun squares but when I am designing a pattern that includes them it makes my head hurt trying to figure out what is the right size. I’m designing a “round” table cloth right now using the Missouri Star block and was beating my head on the table trying to get the right size HST square. Thank you so much. I know other quilters appreciate your chart as much as I do.

  • Posted March 18, 2018 at 12:24 pm | Permalink

    Thank you for this wonderful chart. I appreciate this so much, you have made things so much easier for me. Thank you.

  • Leah Seals
    Posted April 14, 2018 at 4:14 pm | Permalink

    Thank you so much. I have been looking for something that would give me some guidance on how much fabric to purchase and how large/small to make the triangles to achieve the finished results. This has been most helpful.

  • Jo-Ann
    Posted May 20, 2018 at 7:50 am | Permalink

    Thanks! Great tutorial

  • Jean
    Posted July 2, 2018 at 4:09 pm | Permalink

    Thank you so much. I’m getting ready to make my son’s wedding quilt and this eliminates all my guess work.

  • Posted October 17, 2018 at 6:11 pm | Permalink

    Thank you for this! Very handy. :)

  • Susana Lopez
    Posted June 3, 2019 at 6:32 pm | Permalink

    This measurement chart is fabulous, thanks, will save me lots of time

  • Laura
    Posted June 3, 2019 at 8:13 pm | Permalink

    Thank you for this tutorial. I love your site.

  • Diane Beaudoin
    Posted October 1, 2019 at 3:28 pm | Permalink

    Could you put a better copy of the cheat sheet on your webpage? It’s very blurry and hard to read…it’s missing some parts of the numbers.

    • Posted October 1, 2019 at 3:31 pm | Permalink

      Did you download the PDF version of the cheat sheet? The PDF is perfectly clear to see. Thanks!

  • Alma Gaertner
    Posted October 21, 2019 at 10:15 am | Permalink

    Thanks for sharing

    • Joanne
      Posted November 25, 2019 at 7:29 am | Permalink

      I’ve already started my starburst quilt and have 2 squares complete, so making the triangle bigger is not an option for me. Is there another solution of adding more HST to the side and top to make it a twin size, I dont want a lopsided starburst. Can you help me with this dilemma?

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