How many 18x18 tiles will you need to cover 400 sq feet?

Answer 1

Each tile is 2.25 sq ft (1.5 x 1.5 ft), so you will need at least 177.77 tiles. (400/2.25)

Depending on the exact width and length, you will need enough to use partial tiles along one or both edges. An optimum length or width would be one that is exactly divisible by 1.5 feet. If the tiles have a pattern that runs in one direction, you may not be able to use them along both edges, so ideally you should pick the direction that uses the largest percentage of the cut tile, minimizing wasted tiles.

Example : a square room 20 x 20 requires 14 tiles by 14 tiles (196) directionally, but only the absolute minimum of 178 if tiles can be cut into thirds and used on both edges.