# Thread: how do I figure the ending size of half-square triangles?

1. ## how do I figure the ending size of half-square triangles?

I want to make a baby quilt using a half-square triangle pattern, but I am not using pre-cuts. How do I figure out how big the ending squares will be when I sew two squares together and do either the 4-corner diagonal cut or the 2-corner diagonal cut??

For example, if I use 8" squares, sew the perimeters together, and cut twice through the center ending up with 4 half-square triangles, how big will the squares be?

Or if I sew twice down the middle, then cut inbetween those seams, how big will those 2 squares end up?

I can't figure this out in my head. What is the math formula for this?

2. ## Re: how do I figure the ending size of half-square triangles?

There must be a formula somewhere, but I don't know where. But when I am puzzled by math things, I take the hands on approach and cut scrap fabric to 8" square, make the HSTs and then measure. I keep my samples on a big safety pin in my sewing area, notes attached, and I can go back to see the actual block instead of a math computation!

I know a brilliant mathematician will come along to provide a formula. Someone several years ago figured it all out and shared. Wish I knew where that is!

3. ## Re: how do I figure the ending size of half-square triangles?

Here's a couple of suggestions.....I normally go to the internet to find out how to make these things !

http://www.craftbuds.com/quick-triangles-baby-quilt/

Here's another :
http://www.diaryofaquilter.com/2015/...-tutorial.html

Here's Another Idea :
This is a Lattice Baby Quilt.....Really Nice !
http://www.diaryofaquilter.com/2017/...-tutorial.html

Of course you can always look on Craftsy.com
https://www.craftsy.com/blog/2013/06...quilt-designs/

Then too....MSQC has a lot of tutorials....
Here's a Half-Square Triangle "Quilt Snips"
https://quiltingtutorials.com/tutori...orial-easy-hst

4. ## Re: how do I figure the ending size of half-square triangles?

Here's my go-to site for half square triangle size chart, it gives the sizes needed for 2, 4, and 8 triangles

http://www.blossomheartquilts.com/20...maths-formula/

5. ## Re: how do I figure the ending size of half-square triangles?

Originally Posted by Caroline T.
Here's my go-to site for half square triangle size chart, it gives the sizes needed for 2, 4, and 8 triangles

http://www.blossomheartquilts.com/20...maths-formula/
Great chart!

We have talked about this a lot and the consensus (mostly) is to skip the fractions and round up and square up after. I don't want to look for 7/8'' on my ruler, what a pain.

6. ## Re: how do I figure the ending size of half-square triangles?

Thanks Jean! That is a great idea!

7. ## Re: how do I figure the ending size of half-square triangles?

Thank you Hulamoon/Lorie (not sure)! That's a great site for bookmarking! I think I've got it now.

8. ## Re: how do I figure the ending size of half-square triangles?

Originally Posted by StacyLSS
Thank you Hulamoon/Lorie (not sure)! That's a great site for bookmarking! I think I've got it now.
It was Caroline that posted the chart, I just chimed in.

9. ## Re: how do I figure the ending size of half-square triangles?

Many times I make HSTs using the old method of drawing a line diagonally & sewing 1/4" on either side of the line. If you use this method, you'll need to cut your squares at least 1/2" bigger than the size of the desired HST. I usually do 5/8" to allow wiggle room for squaring up the block. I square up every block.

10. ## Re: how do I figure the ending size of half-square triangles?

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