Here's you a quik little reference chart for making the HST's from specifc size blocks - you know where you put 2 blocks right sides together, sew 1/4" from the outside around the outside, then cut 'x' corner to corner...
I made a chevron using this method, used 8" square, finished product was 49x49
http://www.quiltingboard.com/picture...k-t218608.html
I did start out with 10" squares and it was just too big so I carefully cut down to find the finished size I wanted for this particular quilt.
I then found this. I don't remember the blog I found this on but it makes perfect sense and did measure out for what i did cutting down (above):
When you open out and iron them you get perfect half square triangles! It’s amazing every time. The basic math is a HST that is roughly 64% of the size of your original square.
So your math would be this:
Beginning Square Size x 0.64 = HST size.
If you knew the size you needed your HST to be, but wanted to find out how big to cut your beginning squares, you would use this equation instead:
HST / 0.64 = Beginning Square Size.
It’s always a good idea to make a test square before beginning a project, as all of our sewing and cutting varies. Not every size is exactly 64%, but it’s a good place to start without getting too involved in the math.
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