By the Home Savings Calculator team · 29 August 2026 · 6 min read
Measure the area to be tiled: length × height for a splashback or wall, length × width for a floor. Tiles are sold by the box with a coverage figure in square metres, so ordering by area avoids the arithmetic errors that come from counting individual tiles.
Order the whole job in one go. Batches vary in shade, and a top-up ordered three weeks later frequently does not match what is already on the wall.
Put your area into the tile calculator. It adds wastage for your layout, scales adhesive and grout by tile size and surface, and adjusts the labour days accordingly.
Ten percent is the baseline for a straight or stacked layout on a simple wall. Brick bond adds a couple of points. Diagonal adds around five, because every edge ends in a cut. Herringbone is closer to eight, since almost every perimeter tile is cut twice.
Patterned tiles that must align add more again, and a room with lots of alcoves, bays or pipe boxing will waste more than its area suggests.
Adhesive is driven by tile size and notch depth — larger, thicker tiles need a deeper bed, and floor tiles take noticeably more than wall tiles of the same area.
Grout works the opposite way, because it fills joints rather than area. Small tiles and mosaic have far more joint length per square metre, so mosaic can use several times the grout of a large-format tile covering the same wall.
Floor tiling generally costs more per square metre than wall tiling. The tiles are thicker, they take more adhesive, the substrate has to be flatter, and cutting is slower.
Large-format tiles look like less work — fewer tiles, fewer joints — but they are heavy, unforgiving of an uneven substrate, and slow to cut. A tiler will usually lay less area per day in large format than in standard.
Tiles need a flat, sound, dry surface. In a wet room that usually means tile backer board and tanking; on a floor it often means levelling compound. Tiling over a poor substrate is the most common reason a job fails early.
Removing existing tiles is the other line people leave out — it takes real time and generates real waste. Both are switchable in the calculator so you can see what they add. If tiling is one part of a wider job, price the room in the room renovation cost calculator, and compare against flooring costs per m² if you are still deciding between tile and board.
