Tile Calculator
Enter your room's length and width plus your tile's dimensions to find exactly how many tiles to buy, including a waste allowance for cuts and breakage.
Tiles needed
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Enter your room and tile dimensions to calculate.
How the Tile formula works
Area-based tile count:
Room area (ft²) = Room length × Room width Tile area (ft²) = (Tile length in ÷ 12) × (Tile width in ÷ 12) Tiles needed = ceil( (Room area / Tile area) × (1 + waste%) )
Step-by-step calculation
- Calculate the room's total area in square feet.
- Calculate a single tile's area in square feet, converting its dimensions from inches.
- Divide room area by tile area to get the base tile count.
- Increase by your waste percentage (commonly 10%) to account for cuts, breakage, and future repairs, then round up to a whole tile.
Worked example
A 12 ft × 10 ft room (120 ft²) using 12×12 inch tiles (1 ft² each), with 10% waste: Base tiles = 120 / 1 = 120. With waste = 120 × 1.10 = 132 tiles.
Frequently asked questions
How much waste allowance should I use?
10% is a standard allowance for straightforward rectangular rooms. Complex layouts with lots of cuts (diagonal patterns, many corners, small rooms) often warrant 15–20% to be safe.
Should I buy tiles by the piece or by the box?
Most retailers sell tile by the box, covering a certain square footage — once you know your total tiles or square footage needed, check the box coverage and round up to the nearest full box.