Easy Half-Square Triangles Tutorial

There are a number of different ways you can go about constructing your half square triangles, today I'm going to share with you my favourite method. This method makes two half square triangles at one time. I see many people using almost the same method as this, however they cut their squares to the exact size needed, while I choose to cut mine slightly larger than needed. This gives me more accuracy as the measurements are easier to cut and I can square up my finished half square triangles to their perfect size at the end, enabling me to straighten up any blocks that are slightly on the wonky side.

Step one:

Cut one square each of two different fabrics 1 inch larger than the finished size. For example, my finished size was 2 inches and so I started with 3 inch squares. If your finished size needed to be 4 ½ " you would need to cut your squares at 5 ½ ".

I cut two squares of each colour here as I needed a total of four half square triangles.

If you wish to cut your fabric to the exact size now rather than trimming at the end, you need to add ⅞" to your finished size instead of a whole inch. I much prefer to cut mine the whole inch larger than the finished size. It is easier to measure with my rulers, I am able to then trim off the excess at the end to ensure more accurately sized blocks, and the extra fabric wastage is so small it's hardly even worth mentioning.

Step two:

Draw a line diagonally across all the squares of one colour on the wrong side of the fabric. This could be either colour square, it really doesn't matter, I just chose the lighter fabric as it is easier to see the line on.

Step three:

Place the square with the drawn line on top of your other square right sides together, the line should be facing up so you can see it. Now sew a ¼ inch seam along both sides of the line.

Step four:

Cut your blocks in half on the drawn line.

Step five:

Open up your blocks, pressing your seams, either to one side or open, whatever your preference.

Step six:

Trim off extra fabric, ensuring your completed blocks are nice and square. Your blocks should be trimmed to ½" larger than the required finished size. In my case I've trimmed them to 2 ½".

There are so many different designs you can make with half square triangles alone, and hundreds more if you pair them up with other blocks. These four half square triangles I used in the corners of a modified churn dash block for my garden quilt I'm currently working on.

While of course you could just cut out triangles and sew them together to make a square, it is more accurate to sew them first while still a square and then cut them into triangles. This is because you are sewing on the bias of the fabric and if cut first it is much easier for the fabric to become stretched and distorted as you sew than if it is still held together in a square.

I hope this was useful to you, if you have any questions feel free to ask.

Happy quilting!