Tile Calculator
Tile is bought by the box, sized by the piece, and installed with grout and thinset this calculator doesn't estimate — their coverage depends on tile size, joint width, and trowel notch, figures this page doesn't have sourced yet, so they're left out entirely rather than guessed at. What this calculator handles: your room's area, a waste percentage, the tile size you're using, and your box's actual coverage, converted into square footage after waste, a tile count, and a box count. Enter your room's dimensions or a total area you already have, pick your tile size — a product dimension, self-evident from its stated size, no citation needed — and enter your box's actual coverage, since that number genuinely varies by product and isn't standardized the way tile size is. The result rounds up to a whole tile and a whole box, since a partial one still has to be bought.
Your room
Enter your room's dimensions above to see results.
How it's calculated
The calculator resolves your area from either room dimensions (length × width) or a direct entry, then adds a waste percentage on top — covering cut waste from your layout plus attic stock held back for future repairs. That waste-adjusted square footage is divided two independent ways: by your selected tile's area to get a tile count, and by your box's coverage to get a box count. Each is rounded up separately and computed straight from the same waste-adjusted area — the tile count doesn't feed into or depend on the box count, or vice versa. Grout and thinset aren't part of this calculation — see the guidance below for why.
Worked example
A 100 sq ft bathroom floor, 12×24 tile, at the 12% default: waste-adjusted area = 100 × 1.12 = 112 sq ft. At 2 sq ft per tile (12×24), that's 112 ÷ 2 = 56 tiles exactly. At the calculator's default 20 sq ft per box, that's 112 ÷ 20 = 5.6 — rounded up to 6 boxes. Both counts come from the same 112 sq ft independently — the tile count doesn't depend on the box count or vice versa. Check your specific box's actual coverage on its sales sheet rather than trusting this page's round default.
Waste, attic stock, and why grout isn't included
Two different kinds of overage are bundled into one waste percentage on this calculator, and they're worth understanding separately even though they add up to one number. Cut waste is what a layout actually consumes cutting full tiles down to fit against walls, around fixtures, or into a pattern — a diagonal or herringbone layout cuts at more angles than a straight grid and genuinely uses more tile per square foot of floor. Attic stock is a different thing entirely: tile held back, unopened, for a repair months or years down the road. Daltile's own guidance frames overage almost entirely around this — dye lots and printing processes shift over time, so tile bought later to fix a crack or a failed piece may not match what's already on the floor, even from the same product line. MSI's guidance separates the two explicitly: 10-15% for cut waste depending on pattern complexity, plus another 5-10% for attic stock on top of that. A straight-lay layout with no future-repair concerns might reasonably sit near the low end of the published range; a complex pattern in a house you plan to own for decades reasonably sits near the high end.
Grout and thinset aren't part of this calculator, and that's a deliberate scope decision, not an oversight. Both depend on tile size, joint width, and trowel notch — a smaller tile has proportionally more grout lines than a large one, a wider joint uses more grout per square foot, and thinset coverage changes with trowel notch size in a way that isn't a simple function of tile area alone. None of those figures are sourced on this site yet. Rather than publish a guessed coverage rate, this calculator leaves both out entirely — check the specific grout and thinset product's own coverage chart, or ask the tile retailer, for those two materials separately from what this page estimates.
Common mistakes
- Ordering tile with no waste allowance beyond exact cuts. Manufacturer guidance covers two separate things — cut waste from your layout and attic stock held back for future repairs — and skipping either can leave you short or unmatched later.
- Assuming grout and thinset scale simply from tile square footage. Both depend on tile size, joint width, and trowel notch — figures this calculator doesn't estimate; check the product's own coverage chart for those separately.
- Using a straight-lay waste percentage for a diagonal or herringbone layout, which cuts more tile at more angles and needs a higher allowance than a simple grid.
- Trusting a guessed box-coverage number instead of checking the product's sales sheet. Box coverage isn't standardized across tile products, and this calculator's default is a round starting point, not a real figure for any specific tile.
- Skipping attic stock entirely because the initial cut waste seems like enough. Dye lots and printing processes shift over time — tile bought later for a repair may not match what's already installed, even from the same product line.
Where the coverage figures come from
Box coverage for tile varies by product and isn't standardized — Daltile's own guidance is to check the sales sheet on each series page rather than assume a figure. This calculator's box-coverage field is editable for exactly that reason, the same treatment sod's pallet field and the hardwood flooring calculator's box-coverage field both got: it's the feature, not a caveat. No quick-pick presets ship here since no sourced product-specific box-coverage figures exist yet — read your actual box or the product's sales sheet before ordering. Tile size is a different kind of number: it's self-evident from the product's stated dimensions, which is why it ships as a preset list with no citation needed, the same reasoning drywall's sheet sizes have always had.
Read more in our methodology.
FAQ
- How much extra tile should I order?
- Published guidance spans roughly 10-20%. Daltile frames it as about 10% for "attic stock" — tile held back for future repairs, since dye lots shift over time. MSI separates 10-15% cut waste (pattern-dependent) from another 5-10% for repairs. This calculator defaults to 12%, in the middle of that range; increase it for a complex pattern or a house you'll own for decades.
- What's the difference between cut waste and attic stock?
- Cut waste is tile consumed cutting full pieces down to fit a layout — more for a diagonal or herringbone pattern, less for a straight grid. Attic stock is tile held back, unopened, for a future repair, since dye lots and printing processes shift over time and tile bought later may not match. They're different reasons to over-order, and the published waste range covers both.
- Why does tile size have presets but box coverage doesn't?
- Tile size is self-evident from the product's stated dimensions — a 12×24 tile is exactly 2 square feet, no citation needed, the same reasoning drywall's sheet sizes have always had. Box coverage genuinely varies by product and isn't standardized, and no sourced figures exist for it yet, so it ships as a plain editable field instead of a preset list.
- Does this calculator include grout or thinset?
- No, deliberately. Both depend on tile size, joint width, and trowel notch in ways that aren't a simple function of tile area, and this site doesn't have sourced coverage figures for either yet. Rather than guess, they're left out entirely — check the specific grout or thinset product's own coverage chart.
- Why does a diagonal layout need more waste?
- A diagonal or herringbone layout cuts tile at more angles than a straight grid, and more of those cuts land as unusable offcuts rather than reusable partial pieces. The result is genuinely higher material consumption per square foot of finished floor, which is why manufacturer guidance points toward the higher end of the published waste range for these patterns.
- Where do I find my tile box's actual coverage?
- Daltile's own guidance is to check the sales sheet on each product series page — most manufacturers publish per-box coverage there or print it on the box itself. This calculator's editable coverage field exists specifically so you can enter that real figure instead of relying on a generic default.
- Should I order by tile count or by box count?
- By box, in practice — most tile is sold by the box, not individually. The tile count this calculator shows tells you exactly how many pieces the job needs, which is useful for checking a box's stated piece count or planning a cut layout, but the box count is the number you actually bring to the register.