If 12x12 is 144... There would be 144 tiles in a box right?
It depends on how many tiles long you wish to make your rectangle. Once that is determined, multiply your width by your length and you will have the amt of tiles needed. ie: 3 tiles wide and 4 tiles long= 12 tiles
glazed and unglazed
You would have 79 tiles.
Assuming you mean 16x16 inches tiles... 441 tiles would cover the area exactly
You need 27 Box of 9 tiles
297 16x16-inch tiles.
Assuming you mean the tiles are 16 inches square - you would need 169 tiles.
108 plus 20% more.