The tile calculator plans a tiled floor or wall from the area to cover and the tile you have chosen. Enter the length and width of the space, the waste percentage (cuts at edges, around fixtures, and broken tiles), and the tile size — common square sizes are offered in both unit systems — plus how many tiles come in a box and what a box costs. The calculator returns the number of whole tiles, the whole boxes to buy, and the estimated cost. Waste is the decision that matters most in tiling: 10% is the practical floor for straight layouts, and diagonal or offset (running-bond) layouts typically need 15% because edge cuts waste more. The unit toggle switches between inches/feet and centimeters/meters, including the tile size list. The calculator assumes one rectangular area and square tiles; for complex spaces, split into rectangles or add a higher waste allowance. Everything runs locally in your browser — your measurements are never uploaded, logged, or stored.
How is the result calculated?
Bathroom floor: 10 ft × 8 ft with 12-inch tiles
A bathroom floor measures 10 by 8 feet: 80 sq ft. With a 10% waste allowance the area to cover is 88 sq ft. A 12-inch tile covers exactly 1 sq ft, so you need 88 whole tiles. Boxes of 10 tiles mean 8.8 boxes — buy 9 boxes. At $30 per box that is $270 of tile, before thinset, grout, and spacers.
Example input and output | Input | Value |
| length | 10 |
| width | 8 |
| wastePercent | 10 |
| tileSize | 12 |
| tilesPerBox | 10 |
| pricePerBox | 30 |
| Result | 80 sq ft · 88 sq ft with waste · 88 tiles · 9 boxes · ≈ $270 |
What is the formula and its assumptions?
Area to tile
area = length × width
Formula terms | Symbol | Meaning |
length | space length |
width | space width |
Whole tiles needed
tiles = ceil(area × (1 + waste%) / tile area)
Formula terms | Symbol | Meaning |
tile area | side length squared (square tile) |
waste% | allowance for cuts, breakage, and layout |
Boxes to buy
boxes = ceil(tiles / tiles per box)
Formula terms | Symbol | Meaning |
tiles per box | tiles in one box (see the product label) |
What are the most common mistakes?
- Underestimating waste on diagonal layouts — cutting tiles at 45° leaves unusable offcuts on every edge.
- Forgetting that tiles per box is a label figure; some boxes list square footage instead, which you can enter by dividing by the tile area.
- Buying exactly the calculated tiles with no spares — a broken tile a year later means matching a different dye lot.
What are the assumptions and limitations?
- Assumes square tiles and one rectangular area; rectangles must be estimated separately.
- Excludes thinset, grout, spacers, backer board, and labor.
- The waste allowance is a planning figure — actual breakage depends on the tile and the installer.
Where do the numbers come from?
Last reviewed August 4, 2026 · Version 1.0.0 · Toolivaro does not guarantee external content.
Frequently asked questions
How much tile waste is normal?
Straight grid layouts run about 10%; diagonal and offset patterns need 15% because edge cuts waste more. Extra tile is also your repair stock — tile dye lots vary, so keep a few spare tiles from the same batch.
Do I need to include grout lines?
Grout lines are usually small relative to tile size and are covered by the waste allowance. For very large tiles with thin grout joints the effect is negligible; the tile count from the calculator remains valid.
What if my space is not rectangular?
Split the space into rectangles, run the calculator for each, and add the results — then keep the higher waste percentage for the layout complexity.
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