October 26, 2021

32 Half Square Triangles at once

Learn to make 32 Half Square Triangles at once with guest Kelsey of White Rose Designs.

Hi, my name is Kelsey and I am the pattern designer and quilter behind White Rose Designs. I have been sewing for 15 years and started designing my own patterns in September of 2020 after taking Elizabeth’s Pattern Writing course. I am married to my high school sweetheart and we are raising our 2 little girls in South Texas. I’m excited to share how I make 32 HSTs at once, plus a FREE quilt pattern!

Half square triangles are really versatile and common in quilting. I have made so many quilts that require multiple half square triangles that I went in search of a way to make a lot at once to save me time. This is a fun way to make 32 half square triangles at once.

FREE QUILT PATTERN

After reading this tutorial on how to make 32 HSTs at once, you can use it to make my FREE Snap Dragon quilt pattern.

BEFORE GETTING STARTED

A few terms to know before we begin are:

Unfinished size – The size of a half square triangle (HST) all by itself. Before it is pieced in a quilt.
Finished size – The measurement once it has been sewn into a quilt. The finished size is typically a ½” smaller than the unfinished size because you lose ¼” on each side for the seam allowance.

Drawing Lines

To make HSTs that measure 3″ unfinished:

Take (1) 14″ square of 2 different fabrics.
On the wrong side of (1) square, draw a straight line down both the horizontal and vertical centers.

Note: I use a friction pen or pencil for drawing lines. Regular ink pens can bleed onto your fabric.

Draw (1) line from one corner of your 14″ square to the other corner.

Draw (1) more line from the corner of your 14″ square to the other to make an ‘X’ on your 14″ square.

Draw (4) ‘X’s in the 4 quadrants of your 14″ square, as shown below.

PIN AND SEW

Place (1) 14″ square RST with your drawn on 14″ square.

Pin in place to make sure there is no shifting while you sew.

Sew ¼” on both sides of diagonal lines only.
Do not sew ¼” on sides of center lines. See image below.

CUT Half Square Triangles

Cut ON the center lines you drew first, giving you 4 identical squares that are easier to manage.

With each of your 4 squares make 4 cuts:
- 2 diagonal along the drawn line.
- 1 down the center vertically.
- 1 down the center horizontally.

Each of the 4 identical squares with give you 8 HSTs.

FINISHING YOUR HSTs

Now that your HSTs have been cut, press and trim them to measure 3″ squares.

TO MAKE A DIFFERENT SIZE

If you want to make 32 HSTs in a different size, you just need to start with a smaller or larger beginning square.

Reference the chart below for some common measurements.
If the size you want is not on the chart you can also calculate the beginning square size based on what you want the unfinished size of the HST to be.

Calculate: (unfinished HST x 2) + 1”= X, 2X=the size of the beginning square.

Example: If I want my unfinished HST to be 3”. (3×2) =6 +1 = 7, 2(7) = 14”. My beginning square needs to be 14” to make (32) 3” HST.