SettingsSettings for this calculationUS
The total perimeter of the room to be tiled diagonally.
Add up all four (or more) wall lengths at floor level.
The side length of a single square tile.
This calculator assumes a square tile. For a rectangular tile, enter the SHORTER side: the perimeter is divided by this size to count cut positions, so the shorter side gives more positions and the conservative, higher figure, and the longer side gives fewer.
The area of a single tile.
For a square tile, this is the tile size squared (e.g. 0.3m x 0.3m = 0.09 m²).
Extra diagonal corner-cut waste
32.9 sq ft
This estimates the ADDITIONAL waste specific to diagonal corner cuts, on top of your tile layout calculator's base tile count — it is not a replacement for that count.
- Perimeter tile positions requiring a corner cut
- 68
They open the calculator with your figures already in it
Diagonal Tile Layout 45° Corner Cut Waste Calculator: 32.94 sq ft — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- A diagonal (45°) tile layout requires a triangular cut tile at every perimeter tile position; perimeter tile positions ≈ ceil(room perimeter ÷ tile size), and each cut wastes roughly half a tile's area
Inputs used
- Room Perimeter
- 66 ft
- Tile Size (square tile)
- 11.75 in
- Single Tile Area
- 0.97 sq ft
Intermediate steps
- Perimeter tile positions requiring a corner cut
- 68
Confidence note: This estimates the ADDITIONAL waste specific to diagonal corner cuts, on top of your tile layout calculator's base tile count — it is not a replacement for that count.
What this calculation does not cover
- Half a tile per position is an average that assumes the offcut is scrap. In a plain rectangular room the triangle cut off at one wall is often the exact piece wanted at the opposite wall, and a setter who plans the cuts recovers much of it, so this figure is an upper bound there. In a room with alcoves, returns and doorways nothing matches up and the real waste runs above half.
- The setting-out point decides how much of each perimeter tile survives, and it is not in this calculation at all. Shifting the diagonal origin a little turns a row of unusable slivers into generous triangles, and slivers cost more than the geometry suggests — a narrow diagonal cut breaks on the saw more often than it survives, so it is scrapped and cut again. The perimeter length is fixed; where the grid starts is not.
- Assumes every offcut is interchangeable. Directional tile, a wood-look plank, a stone with a run of vein, or a rectified tile laid to a matched pattern cannot simply be turned around to fill the opposite wall, so the offcut recovery that keeps waste near half is unavailable. On top of that sits the breakage rate on long diagonal cuts in hard porcelain, which is a separate loss from the geometric waste counted here.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- A diagonal (45°) tile layout requires a triangular cut tile at every perimeter tile position; perimeter tile positions ≈ ceil(room perimeter ÷ tile size), and each cut wastes roughly half a tile's area
Cite this page
Your workspace
Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.
Tools and safety for this job
To lay floor tile, tile a wall, cut ceramic and porcelain tile, grout and seal tiling and mix adhesive or mortar. Generic types, no brands, no prices.
Protection this work requires
- Cutting or grinding concrete, masonry, screed, tile or fibre-cement board releases respirable silica: cut wet or extract at the tool, and wear a P2/N95 respirator at minimum — a nuisance dust mask does not filter it.
- Wet cement and lime burn skin and eyes painlessly until the damage is done: waterproof gloves to EN 374, safety glasses whenever the mix can splash, and never kneel in wet mix in permeable trousers.
- Saws, grinders and breakers run above 85 dB, where hearing damage accumulates and does not recover: defenders or plugs for every cut, not just the long ones.
- Boards, blocks and bagged material cause most lasting back injuries on small sites: two people or a lifter for full sheets, and never a bag on one shoulder up a ladder.
Show the 15 tools this job needsHide tools
Essential
Chalk line
Grout float and sponge
Manual tile cutter
Mixing bucket or tub
Notched trowel
Paddle mixer
Spirit level
Tape measure
Recommended
Caulking gun
Rubber mallet
Tile nippers
Wet tile saw
Optional
Hole saw set
Laser level
Shovel and spade
Also needed as materials: caulk and sealant cartridges, chalk refill, diamond tile blades, grout sponges.
what each tiling tool is for, and the spec that decides which to buy where one does.