Tile Calculator
Estimate how many tiles you need.
Extra for cuts and breakage (usually 10%).
Results update as you type.
How it works
A tile calculator tells you how many tiles to buy for a floor or wall, starting from the area you need to cover and the size of the tile you have chosen. It first works out the area a single tile spans by multiplying its width and height and converting from square inches to square feet, then divides the total project area by that figure to reach the exact tile count. Finally it adds a waste allowance for cuts and breakage and rounds up to whole tiles, because you cannot buy a fraction of one. That waste step is the reason a tile calculator beats a quick mental estimate. Real installations lose tiles to edge cuts, corners, breakage during handling, and the occasional flawed piece, and dye lots vary between production batches — so ordering the bare minimum almost guarantees a shortfall and a mismatched top-up. The area-divided-by-tile-area method is standard estimation practice because coverage is fundamentally about fitting one area inside another. Homeowners, tilers, renovators and builders reach for a tile calculator when quoting or ordering for a bathroom, kitchen, splashback or whole floor, adding around 10 percent waste for straight layouts and more for diagonal or heavily cut rooms.
Tiles = area ÷ tile area, then × (1 + waste%), rounded up
Tile width times height gives the area one tile covers, divided by 144 to convert square inches into square feet so it matches the project area's units. Dividing the total area by that per-tile area yields how many tiles fill the space exactly. Multiplying by one plus the waste percentage adds spare tiles for cuts and breakage, and rounding up ensures you buy whole, usable pieces rather than fractions.
Source:Standard construction estimation
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter area to cover, tile width and tile height.
- 2
Adjust the options
Adjust waste allowance if they apply — sensible defaults are already set.
- 3
Read your result
Tiles to buy updates instantly as you type — no button to press.
Frequently asked questions
How much waste should I allow for tiling?
Allow around 10 percent for a standard straight or grid layout in a simple rectangular room. Step up to 15 percent for diagonal patterns, herringbone, or rooms with many corners, alcoves and pipe cutouts, because each cut wastes part of a tile. Large-format tiles and intricate mosaics can push waste higher still. When in doubt, add the higher figure — the cost of a few spare boxes is trivial next to halting the job to reorder.
How many tiles do I need per square foot?
Divide 144 by the area of one tile in square inches to get tiles per square foot. A 12 by 12 inch tile covers exactly one square foot, so you need one per square foot. Smaller 6 by 6 inch tiles cover a quarter of a square foot each, so you need four. The tool does this automatically from the tile dimensions you enter, then applies your waste allowance.
Should I buy extra tiles from the same batch?
Yes, always keep a few spare tiles beyond the calculated amount, and make sure they come from the same production batch. Tile colour and finish shift subtly between dye lots, so a future repair using freshly bought tiles can stand out against the original field. Store the labelled spares somewhere safe. Replacing a single cracked tile years later is simple only if you kept matching pieces from the initial order.
Does this calculator work for wall tiles?
Yes. The method is identical for walls and floors — enter the wall area to be tiled and the tile size in exactly the same way. Measure the wall height and width, multiply for the area, and subtract large openings such as windows or a vanity if you like. Walls often use different tile sizes than floors, so calculate each surface separately and add a waste margin suited to its layout and cut complexity.
How do I measure the area to tile?
For a rectangular floor, multiply the room length by its width to get square feet. For an irregular space, split it into rectangles, calculate each, and add them together. For walls, multiply height by width for each wall and sum them, subtracting large openings only if they are substantial. Measure carefully and round area up rather than down, then let the waste allowance handle cuts and the inevitable breakages.