Need some rag quilt help
 

I found some Ninja Turtle flannel today so I am going to make a rag quilt for my grand daughter. I have decided to make a 4 patch one where the main turtle fabric will be cut at 10" squares. Here is where I need the help. What size strips do I need to cut for the 4 patch blocks so that after I cut and sew them together with my 1/2" seam the block will finish out to be 10" like the main turtle fabric. My strip sets for the 4 patches are going to be the colors of the masks of the 4 turtles. Thanks for the help!!

If my calculations are correct you need 5 1/2 in squares

I agree with the above.

I think you should cut 6" because when you have a 1/2" seam on each side, that would give you a finished 5" square which with four of them would give you the 10" finished square you would like. Am I correct or am I missing something??

I agree with cjsews. Your main fabric is cut at 10" squares, so that means (with 1/2" seams for rag quilt) your main fabric will finish at 9". That means each square in your 4-patches will finish at 4.5". With 1/2" seams that means you should cut them at 5.5".

I play a lot with paper before I make one of these. I have one piece the size I want the finished block. Then I'll piece paper to figure out what size the blocks need to be before they are finished.