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Tile Calculator

Find how many tiles and boxes a floor or wall needs, including cutting waste.

Tiles are sold by the box, priced by coverage, and broken by the cut. The single most common tiling mistake is ordering the exact area with nothing spare — then discovering the same tile is out of stock when a cut cracks. This calculator works out the area, the number of individual tiles your chosen size requires, and the boxes to buy, with a waste allowance you control.

Waste is not a fudge factor. Diagonal layouts, herringbone patterns, rooms with many corners and large-format tiles all waste more because offcuts cannot always be reused. Straight grid layouts in a simple rectangle can run at 10 percent; complex patterns deserve 15 to 20 percent.

Calculate

Enter your measurements — the estimate updates as you type.

Estimates for planning and buying only. Product coverage varies by brand — check the label of the exact product you buy.

How to use this calculator

Measure the full area, including under appliances and into doorways you plan to tile.
Enter the exact tile dimensions from the box, not the shelf-edge description.
Set the waste allowance for your layout — 10 percent straight, more for diagonal or patterned work.
Round up to whole boxes, and keep the leftovers: a discontinued tile makes future repairs painful without them.

How tile quantities are calculated

Tiles needed = (area x (1 + waste)) / area of one tile. Tile area in square feet is (length in inches x width in inches) / 144. Boxes = tiles / tiles per box, always rounded up because stores sell whole boxes.

Worked example: A 10 ft x 10 ft bathroom floor is 100 sq ft. With 12x12 inch tiles each covering exactly 1 sq ft, plus 10 percent waste, you need 110 tiles. At 10 tiles per box, that is exactly 11 boxes.

Common mistakes to avoid

Using nominal tile size instead of the real size printed on the box — a '12 inch' tile may be 11.75 inches.
Forgetting the waste allowance, or using a straight-layout allowance for a herringbone floor.
Not checking batch numbers on boxes; tiles vary slightly in shade between production runs.

Frequently asked questions

How many tiles do I need per square foot?

It depends entirely on tile size: four 6x6 inch tiles, one 12x12 tile, or a quarter of a 24x24 tile cover one square foot. Enter your tile size above and the calculator does the conversion.

How much extra tile should I buy?

Ten percent is the standard allowance for straight layouts. Plan 15 percent for diagonal layouts and up to 20 percent for small rooms with many cuts, then keep at least a few spares after the job.

Should I tile under kitchen cabinets and appliances?

Tile under appliances, yes — it makes them easier to slide out. Under fixed cabinets is optional, but tiling the full floor keeps heights even if the kitchen is ever rearranged.

Does grout line width change the tile count?

Slightly. Wide joints mean the tiles cover a touch more area in total, but the effect is small enough that the waste allowance normally absorbs it.

Go deeper: read our guide — How Much Extra Tile Should You Buy? Waste Allowances Explained