How many 18x18 tiles will you need to cover 1020sq ft?

Answer 1

18"x18" is 1.5'x1.5' = 2.25 square feet.

1020 sq feet @ 2.25 sq ft per tile = 453.33... tiles.

So you would need a minimum of 454 tiles.

In real life, though, it would also depend on the shape of the area to be covered. This will determine how many tiles need to be cut, whether or not the offcuts can be used or are waste, etc.