Tile Calculator
Calculate how many tiles you need for a floor or wall, including a waste allowance.
About the Tile Calculator
Tile projects almost always need more tiles than the raw room area suggests, since cuts around edges, breakage, and pattern matching all create waste. This calculator finds the room area, adds a waste allowance, and divides by your specific tile's area to get the number of tiles to buy.
How It Works
The calculator multiplies room length by width to get the area to be tiled, adds your specified waste percentage on top to account for cuts and breakage, then divides that adjusted area by the area of a single tile (converted from inches to square feet) to find the number of tiles needed, rounding up to a whole tile.
Room Area = Length × Width; Tile Area (sq ft) = (Tile Length × Tile Width) / 144; Tiles Needed = ceil(Room Area × (1 + Waste%) / Tile Area).
Worked example
Scenario: A 12 ft × 10 ft floor with 12 in × 12 in tiles and 10% waste.
- Room area: 12 × 10 = 120 sq ft.
- With 10% waste: 120 × 1.10 = 132 sq ft.
- Tile area: 12 × 12 ÷ 144 = 1 sq ft, so 132 ÷ 1 = 132 tiles.
Result: 132 tiles.
Tips and common mistakes
- Use 10% waste for straight layouts and 15% or more for diagonal or herringbone patterns.
- Round up to whole boxes and keep a few spare tiles for future repairs.
- Grout lines are ignored; they slightly reduce the number of tiles needed.
Assumptions & Limitations
- Assumes a standard rectangular room layout without complex cuts around fixtures, columns, or angled walls beyond the general waste allowance.
- 10% waste is a common default for straight-lay patterns; diagonal layouts or intricate patterns often need a higher allowance.
- Complex rooms with lots of corners, fixtures, or a diagonal tile pattern typically need a higher waste percentage than the standard 10% default — consider increasing it for those layouts.
Tile layout, cuts and spare pieces
Tile orders should allow for cuts, breakage and future repairs. Simple straight layouts generally create less waste than diagonal, herringbone or heavily patterned layouts. Check the actual coverage per box, round up to whole boxes, and consider keeping unopened spare tiles from the same batch because shade and sizing can vary between later production runs.