Short answer: It depends on the tile size. A 12 by 12 inch tile covers exactly 1 square foot, so you need 1 per square foot. A 6 by 6 inch tile needs 4 per square foot, and a 12 by 24 inch tile needs 0.5.
| Tile size | Tiles per sq ft | Tiles for 100 sq ft | With 10% extra |
|---|---|---|---|
| 3 x 6 in | 8 | 800 | 880 |
| 4 x 4 in | 9 | 900 | 990 |
| 6 x 6 in | 4 | 400 | 440 |
| 8 x 8 in | 2.25 | 225 | 248 |
| 12 x 12 in | 1 | 100 | 110 |
| 12 x 24 in | 0.5 | 50 | 55 |
| 24 x 24 in | 0.25 | 25 | 28 |
The simple rule
Multiply the tile width by the tile length in inches, then divide 144 by that number. The answer is the number of tiles in one square foot. For a 6 by 6 inch tile, 6 times 6 is 36 and 144 divided by 36 is 4.
Allow for cuts and waste
Add 10% for a straight lay, 15% for diagonal or brick patterns and 20% for herringbone or small rooms. Buy every box from the same production lot so the shade matches, and keep a few spares for repairs.
Worked example
A floor of 80 sq ft in 12 by 12 inch tile needs 80 tiles with no waste. With 10% extra that is 88 tiles, or 9 boxes of 10.
Use the Tile CalculatorEnter your own measurements and get an exact amount.
Frequently asked questions
How many 12x12 tiles do I need for 100 square feet?
You need 100 tiles, or 110 with a 10% allowance for cuts.
How many 12x24 tiles do I need for 100 square feet?
Each covers 2 square feet, so 50 tiles, or 55 with 10% extra.
Does grout change the number of tiles?
Slightly. Wide grout joints mean a few fewer tiles, but the effect is small, so the 10% allowance usually covers it.
Related calculators
Figures are typical planning values. Material sizes, densities and local requirements vary, so confirm with your supplier before ordering.
Last updated October 11, 2026.