Tile Calculator
Number of tiles needed for a floor or wall, including waste.
Tiles needed
132
incl. 10% waste
Floor area
120 ft²
Tiles (no waste)
120
Tile size
12×12 in
- Tiles for the floor91%
- Waste (10%)9%
You need 120 tiles to cover 120 ft², plus 12 extra for the 10% waste allowance.
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How the Tile Calculator works
The Tile Calculator helps homeowners, contractors, and DIYers quickly determine exactly how many tiles are needed to cover a floor or wall area, automatically factoring in a waste allowance for cuts, breakage, and pattern alignment. Enter your room dimensions and tile size, choose a waste percentage, and get a precise tile count and square footage estimate in seconds.
The calculator begins by computing the total area to be tiled in square feet (or square meters). For rectangular spaces, this is simply length multiplied by width. For more complex rooms with alcoves, closets, or L-shaped layouts, you can add multiple sections together. The tool then divides the total area by the area of a single tile to determine the raw tile count needed before any adjustments.
Waste is the most critical factor that separates a professional estimate from a naive one. Even a straightforward rectangular room requires cutting tiles at the edges, and those cut-off pieces are often unusable. The standard waste factor for a basic grid pattern is 10%, but diagonal layouts—where tiles are set at a 45-degree angle—can waste 15–20% because cuts are longer and off-cuts rarely fit elsewhere. The calculator applies waste by multiplying the raw tile count by (1 + waste percentage), then rounding up to the nearest whole tile, since you cannot purchase a fraction of a tile.
Tile size dramatically affects how waste accumulates. Larger format tiles (such as 24×24 inch or 600×600 mm slabs) produce less grout-line waste but generate more off-cut waste at walls, especially in narrow spaces like bathrooms. Smaller mosaic tiles on mesh backing have very low individual waste but higher labor complexity. The calculator accounts for this by letting you input any custom tile dimension, so the math reflects your actual product rather than a generic assumption.
A common mistake is forgetting to subtract areas that will not be tiled, such as a kitchen island footprint, a built-in bathtub, or large cabinetry that sits on the floor before tile is laid. Failing to subtract these inflates your order unnecessarily. Conversely, never round down on your final order—tiles are produced in dye lots, and if you run short mid-project, an exact color match from a new batch may be impossible. Ordering 10% extra and keeping unopened boxes for future repairs is considered best practice by professional tile setters.
Formula
Total Area (sq ft) = Room Length (ft) × Room Width (ft) Raw Tile Count = Total Area ÷ Area per Tile Final Tile Count = CEILING(Raw Tile Count × (1 + Waste Fraction)) Example: 120 sq ft room, 2 sq ft tiles, 10% waste → CEILING(60 × 1.10) = 66 tiles
Pro tips
- Order 10–15% extra for cuts, breakage and future repairs.
Key terms
- Waste Factor
- — A percentage added to the raw tile count to account for cuts, breakage, and pattern alignment losses, typically ranging from 10% for simple grid layouts to 20% for diagonal or complex patterns.
- Square Footage
- — The total two-dimensional area of the surface to be tiled, calculated by multiplying length by width and used as the basis for all tile quantity estimates.
- Dye Lot
- — A production batch of tiles manufactured together, ensuring consistent color and texture; tiles from different dye lots can appear noticeably different even if labeled identically.
- Grout Joint
- — The intentional gap left between tiles that is later filled with grout; its width affects the visual appearance of the floor and slightly reduces the effective coverage area per tile.
- Coverage Area
- — The actual floor or wall surface area that one tile covers, calculated as tile length multiplied by tile width, used to convert total room area into a tile count.
- Field Tile
- — The main body tile used to cover the bulk of a surface, as distinguished from border tiles, trim pieces, or accent tiles that serve decorative or edge-finishing roles.
