Tiles & flooring· 3 min read
How Many Wall Tiles Do I Need — and Where to Start So the Top Row Isn’t a Sliver
A 2.4 × 2.5 m wall with 30 × 60 cm tiles: how many tiles a corner start and a centred layout need, and how to avoid a thin strip of tile under the ceiling.
A bathroom wall 2.4 m wide and 2.5 m high is 6 m² (about 65 sq ft). A 30 × 60 cm tile with a 2 mm joint covers roughly 0.18 m², so the area estimate is 34 tiles. The wall will take more than that — and what matters most is where the cut pieces end up.
Two ways to start
| Start | Whole | Cut | Total | +10 % reserve | Cut strips |
|---|---|---|---|---|---|
| Bottom-left corner | 24 | 12 | 36 | 40 | 594 mm on the right, 84 mm under the ceiling |
| Centre of the wall | 21 | 24 | 45 | 50 | 296 mm at the sides, 192 mm top and bottom |
The tiles are laid landscape here: 600 mm wide and 300 mm high. Eight rows with their joints take 2,416 mm, so starting from the floor leaves a strip only 84 mm high under the ceiling. A strip that thin is hard to cut, snaps easily and sits in the most visible place on the wall.
Why start from the centre
With a centred layout the cut strips are equal on both sides: 296 mm left and right, 192 mm top and bottom. The wall looks balanced and no piece is narrower than a third of a tile. The price: 9 more tiles in the layout, 50 instead of 40 with the reserve.
Fired Earth’s wall-tiling guide works the same way: mark the midpoint of the wall, use a measuring stick marked in tile-plus-joint steps to find where the last whole tile lands, and if you would end up with a row of very small cuts at the top, move the starting batten down so the cuts are balanced top and bottom.
How to do it
- 1Mark a vertical centre line on the wall and step out the tile widths with joints from it.
- 2Decide how high the bottom strip will be — 192 mm in the example.
- 3Fix a straight batten so its top edge sits at the bottom strip plus one joint, and check it with a level. The first full row sits on the batten.
- 4Tile upwards; cut the last row under the ceiling to the actual height.
- 5Once the adhesive has set, remove the batten and cut the bottom row piece by piece — the floor may not be perfectly level.
The whole bathroom, windows and doors
The calculator works on one rectangle. Split the bathroom into walls and enter each one separately — the wall width and the height you will tile to. If you tile only to 2 m, enter 2,000 mm, not the ceiling height; the thin-strip question then applies at the top edge of the tiling, not under the ceiling.
Be careful when subtracting doors and windows. Openings create extra cuts, and the pieces from the opening often cannot be used elsewhere. Leave the opening in and you have extra reserve; subtract it fully and the reserve shrinks. Always mark the cuts around openings on the tile before cutting.
Landscape or portrait?
Turn the tiles portrait (300 mm wide, 600 mm high) and the calculator counts 40 tiles from a corner and 45 from the centre — 44 and 50 with the reserve. This time a corner start would leave a 92 mm strip under the ceiling. Try both orientations with your own wall size; every wall comes out differently.
Workshop tips
- Count each wall separately, add up the tiles at the end and put the reserve on the total.
- Hold the marked measuring stick against every wall before any adhesive goes on — it is the fastest way to see where the cuts will land.
- If a mirror, basin or switch goes on the wall, try shifting the centre line so a joint doesn’t land right next to it.
- Buy from a single batch and keep one box for later repairs.
The calculator counts tiles, not the wall build-up. Choose the waterproofing around the shower and bath, the adhesive and the grout according to the system manufacturer’s data sheets.