half square triangles
 

ok, so my brain has taken a trip and left me behind.
I need to make 1/2 sq triangles finished 4 inches - with a seam allowance at 4.5 inches.
how big of a square do I need to start with ? over size prefered so I can trim down.
do I start with 5 or 5.5 squares????

Thanks for your help.
Happy quilting everyone.

Add 1" to finished size and trim down for accuracy. 4" finished - cut 5". You can cut multiples with other methods.

Here is "my" way taken from American & Patchwork magazine lo those many years ago! Tried to look up a link for it but could not find. Your finished size is 4" so you need 5" squares. Place one color square on top of the other, mark the diagonal line and sew 1/4 inch on either side. One of these will make 2 HSTs.

Where it says + 7/8" use 1", much easier to measure and trim.

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half sq triangles
 

thank you for your help, this is what I thought but my brain just wouldn't agree.

T.farmer

Thank you for reply it is very helpful.
My brain just didnt want cooperate today.
Thanks again
T.Farmer

That happens to most of us. There are lots of helpful people on this board.

I really like the method in which the HSTs are next to each other, not in a square. If you want them to be 4.5 inches, cut strips 4.5 inches wide. Sew the lines for the seams for the first one, then see where the second one will fall and cut there. There is actually less waste this way and dog ears are minimized.

I'm currently working on my first HST project and the problem I'm having is that I am making many HSTs that are all kinds of prints with very few dupes (ideally none) so sadly the "several at a time method" doesn't work so well on this particular quilt. Guess I'll have to come up with another project to try it on ;) The sketches are great though, I've printed them out again to have for reference.

Check out my method for making HSTs

You can sew strips together and then cut out for many HSTs at one time or
You can sew scraps together for one HST at a time.
To make 4" HSTs you'll need a 4" template

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Whatever method you use, I suggest being mindful of your grains so you don't have bias on your outer edges.