help with how much yardage to buy
 

I am making a tee shirt quilt. My squares are 14 1/2" square each. there are a total of 35 squares. I would like to put 1 1/2" strip of fabric between each square. both vertically and horizontly. I will need some more of the same fabric for the borders all the way around the quilt. Now I do not know how much fabric to buy for these spacers and borders . Could anyone help me

Thank You so much. Dorothy