256 tiles
13 boxes with 13 tiles in each
144
650
168
80 if the tiles are 12x12 - 12x12 is one square foot covering 80 you would need 80 tiles
256 tiles
13 boxes with 13 tiles in each
144
650
168
585
549!
375
If the tiles are 12x12 inches square - you would need... 75 !
48 12"x12" tiles for a 7'x7' patio.
If you're talking floor tiles as opposed to wall tiles and by 12x12 you mean they are 12 inches square, then the answer is 300. Because each tile is one square foot and a 15'x20' room is 300 square feet. Simple, eh?