Tile Calculator (Tiles Needed)
Enter the length and width of the area you are tiling, the size of a single tile, and a waste allowance, and this calculator returns how many individual tiles you need, how many boxes to buy, and the total material cost. It is built for a quick, honest shopping estimate — round up, and always keep a few spare tiles for future repairs.
Area to tile
Tile & layout
Boxes & price
Tiles needed
110
100 sq ft ÷ 1.00 sq ft/tile × 110% waste
Boxes to buy
11
Material cost
$330.00
Estimate detail
Tiles vs boxes vs cost
How it works
The area to cover is length × width in feet, and a single tile's area is (tile width × tile height) in inches divided by 144 to convert square inches to square feet. Dividing the surface area by the tile area gives the bare number of tiles, before any allowance for cuts. This is a coverage estimate for a rectangular area; for L-shaped rooms or multiple surfaces, run the calculator once per rectangle and add the results.
A waste percentage is then applied on top. Every real installation loses tiles to edge cuts, corners, breakage during handling, and the occasional bad cut. The calculator multiplies the bare tile count by (1 + waste ÷ 100) and rounds up to a whole tile, because you cannot buy a fraction of one. The Tile Council of North America and most retailers suggest planning for roughly 10% overage on straight layouts and more for diagonal or patterned work.
Finally the tiles are grouped into boxes: the tile count is divided by the tiles-per-box figure on your product and rounded up, since tile is sold by the full box. Multiplying boxes by the price per box gives the total material cost. Note this covers tile only — thinset, grout, spacers, trim, and underlayment are separate purchases.
Frequently asked questions
How much extra should I add for waste?+
For a standard straight (grid) layout on a simple rectangular room, 10% overage is the common starting point and covers most edge cuts and the occasional break. Bump it to 15% or more for diagonal layouts, herringbone or other patterns, rooms with many corners or obstacles, or large-format tiles where a single miscut is costly. Natural stone and tiles from a single dye lot also warrant a larger buffer, because a mid-project reorder may not match. When unsure, err high — leftover full boxes are usually returnable, but a color-matched top-up later often is not.
Do grout gaps mean I need fewer tiles?+
Slightly, yes — the grout joints between tiles add a millimetre or two of coverage per tile, so in theory a room needs a hair fewer tiles than the bare area math suggests. In practice the effect is tiny and is dwarfed by cut waste, so this calculator ignores it on purpose and leans conservative. Treat any grout-gap savings as an invisible extra cushion on top of your waste allowance rather than a reason to buy less.
Should I keep leftover tiles?+
Yes. Always set aside several spare tiles from the same dye lot after the job is done. Tiles crack, furniture gets dropped, and years later a discontinued line or a shifted color batch can make an invisible repair impossible. Keeping even a partial box of attic stock is the cheapest insurance you can buy, which is another reason the built-in waste allowance is there to help rather than something to trim to the bone.