The Eight-at-a-Time Half Square Triangle Calculator
What’s the Math for Eight-at-a-Time HSTs?
Before you start, you’re going to need to know two things:
The Finished size of your HST (that’s the dimension once it is all sewn together)
Whether you want to be exact or have a little extra fabric to trim down to size
The “Exact” HST Formula
The "official" math (aka the in-a-perfect-world-where-I-don't-make-mistakes math) states that you add 1¾" to double your desired finished size HST:
(Finished HST Size x 2) + 1¾" = Starting Square Size
The “Oversized” HST Formula
Since, as we’ve established, I always trim my HSTs down to size (and I assume you do too): just add 2" to two times your finished size and you'll be good to go!
(Finished HST Size x 2) + 2" = Starting Square Size
How to Make Eight-at-a-Time HSTs Step-by-Step
"But, how do I make “No Waste” Flying Geese Four-at-a-Time?" you ask? To start, you are going to need four (4) small squares of fabric (measuring the “Starting Small Square Size in the calculator above) and one (1) large square of fabric (Measuring the “Starting Larger Square Size in the calculator above).
Step 1: draw two diagonal lines (corner to corner) on the back of one of your accent square
Step 2: place your two squares, right sides together
Step 3: sew a ¼" on either side of one diagonal line
Step 4: sew a ¼" on either side of the other line
Step 5: cut your squares in half vertically and then again horizontally
Step 6: cut each quadrant on the diagonal (along the lines)
Step 7: press and trim down to size as needed (to the “unfinished dimensions in the calculator above)
What About Other Ways to make HSTs?
If you’re looking to make Two or Four HSTs at a time, I’ve got the math with step-by-step instructions here: