I recently stumbled across a simple calculator for square in a square blocks on the internet. Don't get me wrong -- I love math! But rather than go back and figure this out again, or find something in my files, I hit the internet.
Quilter's Paradise has developed a simple square in a square calculator. You either enter the inside square or the outside square and their formula calculates everything for you! To get there, click on this link:
Square in a Square calculator from Quilters Paradise.
I was trying to figure out the pieces for a 6" inner square and 12" second outer square. Here's what the calculator gave me:
The first result is for the 6" inner square:
The second is for the 12" outer square:
Now, I can confidently make the blocks I need for an interesting quilt that starts with a double square in a square block.
I hope you can use this calculator too!