Tile Calculator
How many tiles a floor or wall needs, from the area and the tile size, with a cut-and-breakage allowance.
Enter the surface you are tiling and the size of the tile, and this works out how many to buy once cuts and breakages are allowed for.
Your details
10% laid square, 15 to 20 for diagonal or herringbone.
Result
Rounded up, waste included.
- Tiles to cover the areaBefore any allowance for cuts or breakages.
- 80
- Surface areaSquare feet being tiled.
- 80
- Area of one tileSquare feet covered by a single tile.
- 1
About this tool
How Many Tiles Do I Need?Divide the surface area by the area of one tile, then add for cuts and breakages. Here's the arithmetic, how much waste to allow, and why you buy a spare box.
Free download
Tiling Measure & Order SheetMeasure every surface, work out the count, and take the numbers to the shop. Same conversions this calculator uses.
Free, no email required — print it or save it as a PDF.
Share it
Tile Calculator infographicThe key numbers as one image — free to save, share, or embed on your own site with credit.
How this is calculated
Tile size is entered in inches, so each tile covers width x height / 144 square feet, 144 being the number of square inches in a square foot. The tile count is the surface area divided by the area of one tile, then increased by the waste allowance and rounded up. A 10% allowance multiplies by 1.1, so 80 tiles becomes 88. You cannot buy part of a tile. The waste allowance covers cuts at the edges, breakages, and the tiles you keep back for repairs. Ten percent suits a straightforward rectangular room laid square. Diagonal and herringbone layouts produce far more offcuts and want more, and so does a room with lots of corners and obstacles. This assumes a rectangular surface. Grout joints are not deducted, because they make a marginal difference and always in your favour.
Common questions
- How much waste should I allow?
- Ten percent for a rectangular room laid square. Fifteen to twenty for diagonal or herringbone, where every edge tile is a cut. Add more for a room with alcoves, pipework or lots of corners.
- Should I subtract the grout joints?
- No. Joints make each tile effectively slightly larger, so ignoring them errs towards buying a few extra, which is the direction you want to be wrong in.
- Why buy spares I do not need?
- Dye lots change. A tile that cracks in two years is almost never still available in the same batch, and a visibly different replacement draws the eye more than the crack did. Keep a box.
- Tiles are sold by the box. How does that work?
- Boxes list the square feet they cover as well as the tile count. Take the tiles-to-buy figure, divide by the tiles per box, and round up. The same rounding rule applies again.
Take it further with AI
Copy this into ChatGPT or Claude with your own numbers filled in. It hands over the figures this calculator worked out, so the answer is built on real arithmetic instead of a guess.
I used the Tile Calculator at https://www.bfcbrilliance.com/tools/tile-calculator.
What I entered:
- Surface length (ft): ___
- Surface width (ft): ___
- Tile width (in): ___
- Tile height (in): ___
- Waste allowance (%): ___
What it calculated:
- Tiles to buy: ___
- Tiles to cover the area: ___
- Surface area: ___
- Area of one tile: ___
Use those figures as given — they are already worked out, so please don't recalculate or estimate your own. Help me turn them into a plan: what to buy or do, in what order, roughly what it should cost, and the mistakes people most often make with this job.
Where the job touches structure, gas, or electrics, tell me to check local building code and whether a permit or a licensed trade is required.Last updated
Get the next tool.
New tools and guides straight to your inbox. No spam, ever.
Part of a bigger job
How to Estimate a Tiling JobTile count, grout and the awkward shape of a backsplash — why grout depends on tile size rather than floor size, by a factor of six.
Walks through all 3 tiling tools in order.