A 10" square block is going to measure ~14" across when on point (across the diagonal).
(the formula is 1.41 x the size of a side of the square - something to do with pi but I doubt you want the details).
So, for a queen size quilt - let's say you want something around 90" x 110" (that's 15" drop on both sides) -
you'll need 6 blocks across 7 blocks down.
That would be total of 72 blocks, plus setting triangles, plus border to get to your final measurments.
Without a border, that would measure 86x100.