I am trying to make a quilt with triangles cut from squares. The technique is where you sew two squares together on the diagonal and then cut them in half. Using that same technique I've created squares of triangles that I would like to join into blocks. That gives two blocks of varied color. The problem for me is that the quilt size requires that each block be 4 inches in size when the quilt is complete. Can anyone help me with the calculations? What would my beginning measurements have to be or how do I calculate it. I can't find any patterns that make blocks that small. Thanks for any help offered.

I've made a quilt this way, can't remember the size of blocks. But the two squares that you sew together, then cut in half, need to be bigger than the 4 inch square--you're going to lose two seams, so I can't remember that exact figure, if a seam is 1/4", your squares need to be 4 1/2". Make one out of some scraps to be sure. Have fun and good luck!

Thanks so much for the heads up. It's been a long time since I've had to make these adjustments and I know there's a formula but your idea works. Again. thanks much. Have a great day

you want to make hst's by marking two squares on the diagonal, then sewing 1/4 on either side of your mark. then cut on the mark, you get two hst's. if so, you want to finish 4 inchs, you would use 5 inch squares. Trim when cut apart being sure to place the 45 degree line on the sewn seam. i always do mine this way. i hate sewing triangles together.

The directions for doing this can be found at :quilting.about.com/od/quickpiecingtechniques/ss/halfsquaretria.htm

I hope this helps.

Granny
You will need to cut your squares 1 and 7/8 inch larger. So if you're wanting a 4 1/2inch raw (4" finished) block you'll need to cut your squares 5 and 7/8 inches. The 1 7/8 inch will always apply in this application.

Hope this helps.