The Half Square Triangle (HST) quilt block may be one of the most basic blocks but there are so many ways to make them!
Recently I revisited my Sun Salutations quilt pattern (a quilt entirely constructed out of HSTs) and did a bit of math to make a smaller version. Once you know the basic formulas and ways to make a HST, it’s a snap to make these blocks!
HERE ARE 3 WAYS I MAKE HALF SQUARE TRIANGLES (HSTs):
1. Making 2 HSTs at a time (“two-up method”):
Determine the size you want your unfinished HST block to be (the size before you sew your blocks together, taking into account your typical ¼” seam allowance). Add 1″ to that number. This is the measurement you want to cut the squares to make your two half-square triangles.
formula:
UNFINISHED HST BLOCK + 1″ = SQUARE SIZES TO MAKE HSTS USING THE TWO-UP METHOD
example:
* When making half-square triangles, I always like to square up my blocks before I use them. I find that this helps make block alignments precise and enables me to have better results when piecing my half-square triangles together. I also make my HSTs with more fabric than some other quilters do. While there is a bit more waste, adding this extra amount makes for a less frustrating trimming experience, especially if my ruler slips a bit and I need to make a second cut. I recommend making a couple of test HSTs before cutting all of your fabric. You may find that you are comfortable starting with smaller squares of fabric.
how to make 2 HSTs at a time:
After stitching and trimming on the line between the stitches, press seams. I like to press the seams on my HSTs open. Then, square up your HST blocks to your desired size.
2. Making 8 HSTs at a time (sometimes called the “Magic 8” method):
Determine the size you want your unfinished HST block to be (the size before you sew your blocks together, taking into account the ¼” seam allowance). Add 1″. Then, multiply that number by 2. This is the measurement you want to cut the squares to make your half-square triangles.
formula:
(UNFINISHED HST BLOCK + 1″) X 2 = SQUARE SIZES TO MAKE HSTS USING THE “MAGIC 8” METHOD
example:
* When making half-square triangles, I always like to square up my blocks before I use them. I find that this helps make block alignments precise and enables me to have better results when piecing my half-square triangles together. I also make my HSTs with more fabric than some other quilters do. While there is a bit more waste, adding this extra amount makes for a less frustrating trimming experience, especially if my ruler slips a bit and I need to make a second cut. I recommend making a couple of test HSTs before cutting all of your fabric. You may find that you are comfortable starting with smaller squares of fabric.
how to make 8 HSTs at a time:
After stitching and trimming on the line between the stitches, press seams. I like to press the seams on my HSTs open. Then, square up your HST blocks to your desired size.
3. Making HSTs with strips of fabric:
Determine the size you want your unfinished HST block to be (the size before you sew your blocks together, taking in account the ¼” seam allowance). This is the minimum measurement you want to cut the widths of the strips to make your half-square triangles.
formula:
UNFINISHED HST BLOCK = STRIP WIDTH TO MAKE HSTS USING THE STRIP METHOD*
*for unfinished HSTs that are 2½” or smaller, add an extra ¼” to the strip width as indicated in the chart below.
example:
* When making half-square triangles, I always like to square up my blocks before I use them. I find that this helps make block alignments precise and enables me to have better results when piecing my half-square triangles together. I also make my HSTs with more fabric than some other quilters do. While there is a bit more waste, adding this extra amount makes for a less frustrating trimming experience, especially if my ruler slips a bit and I need to make a second cut. I recommend making a couple of test HSTs before cutting all of your fabric. You may find that you are comfortable starting with smaller squares of fabric.
how to make LOTS of HSTs at a time using the strip method:
After stitching and trimming on the line between the stitches, press seams. I like to press the seams on my HSTs open. Then, square up your HST blocks to your desired size.
Half Square Triangle Quilt Patterns to Try:
Here are some project ideas:
Stone Slice quilt. Get the pattern here!
Leaf Peepers quilt and runner. Get the pattern here!
Little Fishies quilt and runner. Get the pattern here!
Shifted Houndstooth placemats. Get the pattern here!
Sun Salutations quilt. Get the pattern here!
4 Comments
I have a question. I love your wonderful different direction and design of your quilting stitches. How do you treat your end threads? Do you actually bury each and every thread in the pattern? Burying threads is not my favorite part of quilting.
Hi Shirley, It depends! If I’m in a rush, I typically choose an edge to edge quilting plan. If it’s a special quilt or I want to do a special quilting plan, I do bury each thread. There are definitely quicker ways to do it, but I actually don’t mind burying threads. I highly recommend quilting it a way that is enjoyable for you. Keep stitching! Sheri
Hi Sheri! Apologies that I’m late to the HST party! I got behind on reading your blog posts. Re: your strip method for half square triangles, are you measuring 45 degree angles from the seam line and then cutting on that line, or how do you know where to cut? Did I miss something obvious? Thank you!
Hi Peggy, Thanks for the question. I recommend making your first cut at a 45 degree angle close to the lower left hand of the strip. Each cut after that I rotate the ruler so that the point is aligned with the sewn seam (essentially making a 90 degree angle). There’s no need to measure since the width of the strips you started with determine your HST size (see chart). When you have a moment, take a closer look at the cutting diagram above. Happy stitching!