Tile Calculator

How to calculate how many tiles you need

1. Measure the length and width of the floor or wall in feet and multiply them to get square feet.
2. Multiply the tile length by its width in inches and divide by 144 to get the area of one tile in square feet.
3. Divide the room area by the tile area, then add extra for cuts and breakage.

Tiles = (room area ÷ tile area) × (1 + waste %)

Worked example

A 12 × 10 ft bathroom floor is 120 ft². A 12 × 24 inch tile covers 2 ft², so you need 60 tiles. With 10% extra that is 66 tiles.

How much extra tile should I buy?

Layout	Extra to add
Straight lay, square room	5–10%
Rooms with many corners or obstacles	10–15%
Diagonal layout	15%
Herringbone or chevron	15–20%

Keep a few spare tiles after the job. Tile colours vary between production batches, so matching a broken tile years later can be hard.

Tiles per square foot by size

Tile size	Tiles per ft²
4 × 4 in	9
6 × 6 in	4
12 × 12 in	1
12 × 24 in	0.5
24 × 24 in	0.25

Frequently asked questions

How many 12×24 tiles do I need for 100 square feet?

Each 12 × 24 tile covers 2 square feet, so you need 50 tiles, or 55 with 10% extra.

Do I include grout lines in the calculation?

For most tiles, grout lines are thin enough to ignore. They slightly reduce the number of tiles needed, which acts as a small safety margin.

How do I measure an L-shaped room?

Split it into two rectangles, find the area of each, and add them together. Then enter the total as length × 1.

How many tiles come in a box?

It varies by size and brand. The box label shows both the number of tiles and the square feet it covers. Enter tiles per box to get the number of boxes.

Should I buy all the tile at once?

Yes. Buying everything from the same batch (lot number) keeps the colour and size consistent.