144/2.25=64. 18x18 tile cover 2.25 sq ft area.
The answer depends on the measurement units used for 18x18.
The best way to figure out how many 13x13 tile will be needed to cover 30 sf of floor is to calculate 13x13/144 give coverage per tile (1.1736), then take 30/1.736 = 25.56 tiles.
4 to 5.00 per sf
18 inches = 1.5 ft, so each tile is 2.25 sq ft, number required = 249/2.25 = 111
2.25 square feet
It is not clear what is meant by an "18x18 square feet" tile. 18ft * 18 ft = 324 square feet, so that one tile will be more than enough. An 18 inch by 18 inch tile cannot be a 18x18 square feet tile.
144/2.25=64. 18x18 tile cover 2.25 sq ft area.
You would need 800 tile assuming you had no waste at all. Since this is unlikely you will need 825 tile.
To determine how many 18x18 inch tiles are needed for a 42 square foot bathroom, first convert the tile size to square feet. An 18x18 inch tile is 1.5 feet by 1.5 feet, which equals 2.25 square feet per tile. Then, divide the total bathroom area (42 square feet) by the area of one tile (2.25 square feet): 42 ÷ 2.25 = 18.67. Since you can't use a fraction of a tile, you would need 19 tiles to cover the bathroom.
To determine how many 18x18 inch tiles you need for 56 square feet, first convert the tile size to square feet. An 18x18 inch tile is 1.5x1.5 feet, which equals 2.25 square feet per tile. Next, divide the total area needed (56 sq ft) by the area of one tile (2.25 sq ft): 56 ÷ 2.25 ≈ 24.89. Therefore, you will need 25 tiles to cover 56 square feet.
The diagonal of an 18x18 tile is 18*sqrt(2) = 25.46 units.
Assuming 18x18 refers to 18inch*18inch and not some other measure, each tile is 1.5'*1.5' = 2.25 sq ft So number of tiles required = 150/2.25 = 66.66... ie 67 tiles. That is the mathematical answer. However, this assumes that the 150 sq ft area is a "well behaved" shape and that there are few awkward curves and corners around which the tiles have to be fitted. In real life it is sensible to allow for 10% wastage.
160 of them.
To determine how many 18x18 tiles are needed for 120 square feet, first calculate the area of one tile. An 18x18 tile has an area of 2.25 square feet (18 inches = 1.5 feet, so 1.5 ft x 1.5 ft = 2.25 sq ft). Next, divide the total area by the area of one tile: 120 sq ft ÷ 2.25 sq ft/tile ≈ 53.33. Therefore, you would need approximately 54 tiles to cover 120 square feet, accounting for some extra tiles for cuts or waste.
It would take approximately 311 tiles plus 5% to 10% waste depending on how you lay your floor out and how many cuts you will have.
To cover 720 sq feet of floor with 18" x 18" tile, you would need 320 tiles.