Tile Calculator
Count the tiles for a floor or wall from the area, tile size and grout joint, with your own waste allowance.
Tiles needed
79
- Area to tile
- 80.0 sq ft
You need 79 tiles to cover 80 sq ft, including a 0% waste allowance.
Calculation breakdown
| Step | Formula | Result |
|---|---|---|
| Area | 10 × 8 | 80.00 sq ft |
| Area covered by one tile and its joint | (12.125) × (12.125) | 147.016 |
| Tiles | 80 × (1 + 0%) ÷ area of one tile and joint, rounded up | 79 |
How it works
Enter the area to tile, the size of one tile and the grout joint. Add your own waste allowance if you want one, and the tiles per box and price in the advanced options.
Worked example
A 10 ft by 8 ft floor with 12 inch square tiles and a 1/8 inch joint:
- Area: 10 × 8 = 80 sq ft = 11,520 sq in
- Area per tile and joint: (12 + 0.125) × (12 + 0.125) = 147.02 sq in
- Tiles: 11,520 ÷ 147.02 = 78.4, which rounds up to 79 tiles
With a 10% waste allowance of your own: 11,520 × 1.10 ÷ 147.02 = 86.2, so 87 tiles.
Rounding
Tiles and boxes are always rounded up to whole numbers.
Sources
Frequently asked questions
How do I calculate how many tiles I need?
Multiply the length by the width to get the area, then divide by the area one tile covers, including its share of the grout joint. A 10 ft by 8 ft floor is 80 square feet, which takes 80 tiles that are 12 inches square with no joint. Round up to whole tiles.
How much extra tile should I buy?
This calculator does not assume a figure. Enter your own waste allowance for cuts and breakage, or leave it at 0 for an exact count. The right amount depends on the layout, the room shape and the tile, so ask your installer or the tile manufacturer.
Does the grout joint change the tile count?
Slightly. Each tile covers its own face plus a share of the joint, so a wider joint means fewer tiles. With 12 inch tiles and a 1/8 inch joint, 80 square feet needs 79 tiles instead of 80.
How do I tile a wall or backsplash?
Measure the wall's width and height and enter them as the length and width. Subtract any windows or doors by tiling each wall section separately and adding the counts, since the calculator treats the area as one rectangle.
How many boxes of tile do I need?
Enter the number of tiles in a box in the advanced options. The calculator divides the tile count by that number and rounds up to whole boxes. Tiles are often sold by area, so check the box label for its tile count.
Estimates only. Layout, cuts and breakage vary, so confirm the quantity with your installer before you order.