Is it an 8 inch finished square or 7 1/2 finished? Do you want a drop or just to cover the top of the bed? There are several charts on the net that will give you the finished quilt size. You may just want to measure the bed and the drops. I have a queen size bed and with drops almost to the floor on THREE sides, it is 104 by 94. So in my case you would need 12 times 13 of the 8 inch finished squares which is 156 squares.