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Roughly Built

Tile

Tile Calculator

Figure how many tiles to buy for a floor or wall — area, tile size, and waste by application, with the working shown. Same intent whether you searched tile calculator, tile sq ft calculator, floor tile calculator, or tiles calculator.

Application

Straight floor layout. Waste starts at 10% — raise it for awkward rooms.

ft
ft
in
in
%

Judgment call, not a precise constant — the trade does not publish public waste tables the way bag yields or grout charts do. Defaults are field conventions: 10% floor, 15% wall/shower, 20% diagonal/pattern. Edit to match your room.

sq ft

User-supplied from packaging — not a site preset. Box coverage varies by SKU.

Buy

110

tiles

110.0 sq ft to order (incl. waste)

The working

Area 10 × 10 ft = 100.0 sq ft

+ 10% waste = 110.0 sq ft to order

Tile 12″ × 12″ = 1.000 sq ft each

110.0 ÷ 1.000 → 110 tiles (rounded up)

Start with area, not the carton

Pros start with the surface, not the box. Measure the floor or wall in feet, multiply for square footage, then decide how much overage the layout will burn. Only after that do they convert to tiles or boxes. The common DIY miss is ordering exact net area — every cut edge and every broken piece comes out of that order, and a mid-job reorder often lands in a different dye lot.

Dye lots matter more than people expect. A second order of the “same” SKU can shift shade enough to show on a continuous floor, especially on large-format porcelain. That is why attic stock for future repairs is a different decision from cut waste during install — both may land near 10%, but they are not the same reason to buy extra, and only one of them belongs in this calculator’s waste field.

Waste is a judgment call, not a published table

Unlike bagged concrete yields or manufacturer grout coverage charts, the trade does not publish a free public table that says “use X% for this pattern.” Field practice clusters around roughly 10% for a straight floor, more for showers and walls with fixtures, and more again for diagonal or busy patterns — but your room wins over any default. The percentages here are labeled trade conventions you can edit, not TCNA Handbook cells.

A shower surround is rarely a clear rectangle. Niches, benches, curbs, and valve cutouts multiply cuts; a single flat accent wall does not. Large-format tile can need a higher cushion even on a straight lay because each bad cut throws away more face area. Diagonal fields waste triangular scraps that almost never reuse cleanly — that is why the diagonal mode starts higher than floor or wall/shower.

Why this tool will not invent box coverage

Thousands of SKUs print different square feet per carton. Fabricating a handful of brand presets would be dishonest the way Quikrete bag yields are not — those three sizes really do share published numbers. Enter sq ft per box from your packaging if you want a box count; otherwise trust the tile count and order square footage.

Drop-ceiling grids are a different product with different math. Install labor and thinset coverage are also out of scope here. Once the tiles are counted, joint fill belongs on the grout calculator, which uses each manufacturer’s own coverage chart instead of a generic rate.

Sources

Frequently asked questions

How many tiles do I need for a 10x10 room?

A 10 ft × 10 ft floor is 100 sq ft. With 12″ × 12″ tile and the usual 10% floor waste, you order about 110 sq ft — 110 tiles. Smaller tiles raise the count; larger tiles lower it. Run your actual tile size above.

How do I calculate tile square footage?

Multiply the length and width of the surface in feet for net square feet. That is your tile sq ft calculator figure before waste. Then add overage for cuts and breakage, and divide by the face area of one tile (width × length in inches ÷ 144) to get a tile count rounded up.

How much extra tile for a shower?

Shower and wall work usually needs more overage than a simple rectangular floor because every niche, curb, valve, and corner takes cuts. This tool defaults wall/shower waste to 15% as a field convention — raise it further for a busy surround, or lower it if the layout is a single flat wall.

How much waste for diagonal tile layout?

A 45° layout cuts every perimeter tile on an angle, and triangular offcuts rarely reuse cleanly. Pros commonly plan around 20% for diagonal or other pattern layouts. That is a trade judgment, not a published table — adjust for large-format tile or a simple room.

How many boxes of tile do I need?

Boxes are not universal: every SKU prints its own square feet per box. Enter that number from your carton and the calculator converts order square footage into whole boxes. Without it, trust the tile count and square footage — do not guess a brand coverage rate.

Is a floor tile calculator different from a wall tile calculator?

The area math is the same — length × width of the surface. What changes is waste: floors in a simple rectangle often run near 10%, while walls and showers need more for fixtures and edges. Use one tool, switch the application mode, and keep the waste editable.