Bathroom Tile Calculator

About Bathroom Tile Calculator

A bathroom needs a larger waste allowance than any other room in the house, which is why this page starts at 15 percent rather than the usual 10. The reason is the number of cuts. A bathroom floor has to work around a toilet pan, a basin pedestal, a bath panel and often a shower tray, and every one of those means shaped cuts where the offcut is rarely usable elsewhere. Walls are worse still, with cuts around a window reveal, a shower valve, pipe penetrations and the top of a splashback. Bathrooms are also small, and small rooms have a high ratio of edge to area, so the proportion of tiles that need cutting at all is much higher than in a large open floor. Measure walls and floor separately rather than as one figure, since they usually take different tiles and different quantities. For the walls, measure each wall individually and subtract the door and window rather than using the room perimeter, because in a small room those openings are a large fraction of the total. Buy the full quantity in one batch, since tile shades vary between production runs. For a specific tile size see 30x30 Tile Calculator.

How to use Bathroom Tile Calculator

  1. Enter the floor or wall area dimensions in metres
  2. Enter tile length and width in centimetres
  3. See tile count and optional box count in metric and imperial

Frequently Asked Questions

How much waste should I allow for bathroom tiles?
Fifteen percent is a sensible starting point, against 10 percent for a plain rectangular room. Bathrooms have many shaped cuts around fittings, and those offcuts are rarely reusable.
Should I calculate walls and floor separately?
Yes. They usually take different tiles and different quantities, and mixing them into one figure makes it impossible to order correctly. Measure each wall individually and subtract the door and window openings.
Why do small rooms waste more tiles?
Because the ratio of edge to area is higher. In a small room a large proportion of tiles touch a wall or a fitting and need cutting, whereas a big floor has many full tiles in the middle.
Should I buy all the tiles at once?
Yes. Tile colour varies slightly between production batches, and a top-up bought later may not match. Buying the full quantity including waste in one order avoids a visible difference.
Do I need to allow for the area behind the bath?
Only if you are tiling it. Many installations tile down to the bath edge and no further, so measure the surface you will actually cover rather than the full wall height.

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