If there’s one block in all of quilting that you should know how to make, it’s the Half Square Triangle (HST).  To me, it’s the most versatile block in quilting and you can do endless things with it in design.  With this one block, I can make a wide variety of quilts. In this post, I’m going to show you the Traditional Method of making them, two at a time.  In my next post, I will show you a way of making them four at a time.

This technique is simple and easy to learn and is actually very quick after you get an “assembly line” system going.  Two squares of fabric are cut, placed right sides together (RST), sewn from corner to corner and cut apart.  You end up with two HST blocks.

To figure out what size to cut your squares of fabric to sew these up with, you need to determine what size you want your working (finished) blocks to be (before sewing them into your quilt). When you determine what size you want your working blocks, just add one inch.   Lots of people recommend that you add 7/8″ to the desired size, but I like to add one whole inch. I want a little bit of extra fabric in the end so that I can square up my blocks nicely and it makes the calculations easier.  So if you want a finished working block size of 6.5″, you need to cut squares of fabric that are 7.5″.  (Remember that after you sew your 6.5″ finished blocks into your quilt, you will lose the half inch in the seams and they will be 6″ blocks in your finished quilt.)
With this method, you don’t need any chart to figure out how big to cut your squares.

Desired Finished Block Size + one inch = how big to cut your squares

This method makes two HSTs at a time.