Areas
Wall tiling area less openings (up to four walls)
- where
- gross wall area (m²)
- lengths of the walls to tile (m)
- tiled height (m)
- area of openings deducted (m²)
- number of identical openings
- opening width and height (m)
- net tiled wall area (m²)
Explain this equation
Works out the wall area you actually need to tile in a bathroom, kitchen or shower: the walls you are covering, to the height you are going, less doors and windows.
L1 to L4 are the lengths of each wall you are tiling and H is the height the tiles go up to. Their product Ag is the gross area as if the walls were solid. Ao is the area of the openings: n openings, each Ow wide and Oh high, that will not get tiles.
Area is length times height, and adding the wall lengths first is the same as working each wall out separately and adding them, as long as they are all tiled to the same height. Subtracting the openings leaves the net area.
Sense check: a 2.4 × 1.7 m bathroom tiled full height to 2.4 m on three walls is about 15.6 m² gross; a standard 762 × 1981 mm door takes off about 1.5 m².
Watch out: on half-height tiling only deduct the part of an opening below the tiled height. Reveals, sills and bath panels are extra and need adding.
Net wall area to tile: the run of walls times the tiled height, less doors, windows and other openings.
Enter your values to see the result.
Good to know
Measure each wall at the height you will tile to (half-height, full height, splashback). Enter 0 for walls you are not tiling. If openings differ in size, run the calculator once per size or add them up and enter one opening of the total area. Bath panels, window reveals and boxing-in are extra areas: add them separately.
Common mistake
Deducting the full door opening on a half-height wall. Only deduct the part of the opening that falls inside the tiled height.
Limits
Rectangular walls only. Sloping ceilings and gable ends need splitting into rectangles and triangles first. Does not add waste: apply that in the tile count calculator.
Sources
Results are calculations from the published methods and manufacturer figures shown, and depend on the data you enter. Always follow the tile, adhesive and grout manufacturers’ instructions, BS 5385 and the Tile Association guidance. Coverage rates vary by product and substrate. Check prices and VAT rules with your own records and HMRC.