I would like to make a d9p which finishes at 12 1/2 inches square. I know if I use 4 1/2 squares I will end up with a 12 1/2 inch nine patch, but I will have to cut it in two directions to make the d9p. Anyone know what size squares I need to start with to end up at 12 1/2 inches square?

Thanks for any help you can give me.