No shel will not have enough tile. If you don't know the dimensions of the actual tile how will you solve. If you have a closet 18 square feet it could be 9 ' x 2 ' = 18 square feet. If the tiles were 12" x 6" you would need 36 tiles. If the closet was 6' x 3' = 18 square feet you could have the tiles 12" x 6" = 36 tiles. So you need to know the dimensions of the tile.