Estimate how many tiles you need for a floor or wall from the area and your tile size, with a waste factor for cuts and breakage.
tiles = area_ft² ÷ (tile_l × tile_w ÷ 144) × (1 + waste)
Divide the area by the area of one tile (tile length × width in inches, divided by 144 to get square feet), then add waste.
Use 10% for straight-lay, 15–20% for diagonal or patterned layouts — they need more cuts.
An 8 x 10 ft floor is 80 square feet. With 12 x 12 inch tile (exactly 1 square foot each), you need 80 tiles before waste. A straight-lay pattern carries 10% waste for cuts at the walls, so order about 88 tiles.
If you run the tile on a 45-degree diagonal, every edge tile is a cut and waste jumps to 15-20% — order 92-96 tiles. Buy from a single lot number so the shade matches, and keep a few spares after the job for future repairs.
Coverage is exact geometry. TCNA recommends 10% waste for straight-lay tile and more for diagonal or large-format layouts.
Tile count is area divided by tile face area, but layout drives waste. A diagonal or running-bond pattern needs more cuts than a straight grid; large-format tiles waste more per cut because each offcut is bigger. Add 10% for straight layouts and 15% or more for diagonal, herringbone, or large-format tile.
Beyond the tiles, you need thinset mortar and grout, both estimated by coverage. Thinset coverage depends on trowel notch size and tile size; grout depends on tile size and joint width — small mosaics with wide joints use far more grout than large tiles with thin joints. Buy from one dye lot for both tile and grout to avoid color shifts.
100 tiles before waste — each 12×12 tile covers exactly 1 square foot.
Divide the area by the face area of one tile and round up, then add 10% waste for a straight layout or 15% or more for diagonal, herringbone, or large-format tile.
Both are estimated by coverage. Thinset coverage depends on trowel notch and tile size; grout depends on tile size and joint width, with small tiles and wide joints using considerably more grout.
Yes, beyond the waste factor keep a few spare tiles from the same dye lot for future repairs, since a later batch will not match the color and finish exactly.