Buying ceramic tile for floors requires measuring and math. Estimate how many ceramic tiles to buy by calculating the total floor area you plan to cover and dividing that number by the size of one tile. Ceramic floor tiles typically come in 4-, 6-, 9-, 12-, and 18-inch squares.

1. 1. Determine the square footage of the room (don’t forget the closets!); just multiply the room’s length by its width.

[Length of Floor] x [Width of Floor] = Total Area.

2. Choose your tile size from the following list and use the accompanying equation to figure out the number of tiles to buy:

4-inch tiles:

Total Area ÷ 0.1089 = Number of 4" tiles needed

6-inch tiles:

Total Area ÷ 0.25 = Number of 6" tiles needed

9-inch tiles:

Total Area ÷ 0.5625 = Number of 9" tiles needed

12-inch tiles:

Total Area = Number of 12" tiles needed (You’ve measured your room in square feet, and a 12-inch tile is 1 square foot)

18-inch tiles:

Total Area ÷ 2.25 = Number of 18" tiles needed

Because there are variations in the color of tiles from one tile run to another, buy enough tiles to complete the job and have some leftovers for later repairs.

You can always bring your room dimensions to a tile dealer, who can help you figure out how much tile and other supplies to purchase.