RenoPeek

Tile calculator

Enter the area and the tile size, and this returns how many tiles to order including waste. The waste factor does most of the work here: the same floor needs 10 percent extra in a straight lay and closer to 20 percent in herringbone.

Surface and tile

Order this many

Enable JavaScript to calculate, or use the formula belowArea divided by tile size, plus waste — printed below so it works on paper.

Nothing you type here is sent anywhere. The arithmetic runs on your device and the page makes no network request — see the privacy note.

The formula

Area divided by the coverage of one tile, multiplied by one plus the waste factor, rounded up. A 10-by-4-foot backsplash is 40 square feet; with 12-by-12-inch tiles covering a square foot each, that is 40 tiles before waste and 44 at ten percent.

Tile is sold by the box, not the piece, so the last step is always rounding up to whole boxes. Boxes typically hold 10 to 15 square feet depending on tile size, and the box count is what actually determines what you carry home.

Grout is not in this count and does not follow the same arithmetic: it depends on joint width and tile thickness rather than on area, which is why the grout calculator is a separate tool.

Why the pattern decides the waste

In a grid layout the piece cut off at the wall usually starts the next row, so waste is mostly breakage and the occasional chipped tile — around ten percent. In herringbone every cut is angled, and an angled offcut almost never fits another position, which is why the same floor area can need twice the overage.

HomeAdvisor's published guidance is 10 to 15 percent, covering installation damage and future repairs. The twenty percent figure for herringbone and chevron above is a working rule extending that logic to patterns that source does not price separately, and it is labeled as such rather than presented as a published number.

TileCoverage eachTiles per 40 sq ft, before waste
3 × 12 in subway0.25 sq ft160
4 × 12 in subway0.33 sq ft121
12 × 12 in1 sq ft40
12 × 24 in2 sq ft20
24 × 24 in4 sq ft10

Why labor drives the bill, not the tile

Worth knowing while you choose a pattern, because it changes what the waste factor is costing you. Almost none of the hours go into placing tile — they go into removing what was there, leveling the substrate, waterproofing where water will be, and setting out the layout so the cuts land somewhere defensible.

That is why a harder pattern costs more than the extra tile it wastes: it adds setting-out time on top of material. The full breakdown, with the published rates for labor, material and preparation, is in what tile installation costs.

Where tile fits in the room

Tile is usually a line inside a larger renovation rather than a project on its own. In a bathroom it competes with fixtures and plumbing for the budget — what a bathroom remodel costs lays out that split. If the tile is going on a floor, the flooring calculator compares it against the alternatives, and the remodel cost calculator gives the whole-room figure.

Questions people ask

How many tiles do I need?
Divide the area to be covered by the area of one tile, then add a waste factor. A 12-by-12-inch tile covers exactly one square foot, so a 40-square-foot backsplash needs 40 tiles before waste and 44 to 46 after it. HomeAdvisor recommends ordering 10 to 15 percent extra for breakage and future repairs.
How much extra tile should I order for a diagonal layout?
Take the top of the range rather than the bottom. A straight lay wastes about 10 percent because offcuts start the next row, while a diagonal layout produces triangular offcuts that fit nowhere else. Herringbone is worse again. Ordering short on a patterned floor usually means a dye lot mismatch on the reorder.
How many boxes of tile should I buy?
Divide the area you are ordering, waste included, by the coverage printed on the box — usually 10 to 15 square feet — and round up. Buying by the box is what actually happens at the counter, and it is why the calculator returns an area as well as a tile count.
Why is tile labor so much more than the tile?
Because most of the work happens before any tile is set. Substrate preparation, waterproofing, leveling and layout account for the bulk of the hours, and HomeAdvisor prices demolition and prep separately at $2 to $7 per square foot. A tile that costs $4 can easily carry $10 of labor on an uneven floor.
Should I keep leftover tile?
Keep one full box, sealed, for as long as you own the room. Tile dye lots vary between production runs, and a tile bought two years later to replace a cracked one will usually be visibly different. This is the strongest practical argument for ordering at 15 percent rather than 10.
Sources