KEY TAKEAWAYS
- Tiles per m² is simple division — 11.1 for 300 × 300, 2.8 for 600 × 600 — before joints and wastage.
- Wastage is set by the layout: 5% straight, 10% with cuts, 15% diagonal or pattern.
- Order everything in one lot from one batch — a top-up box from another batch rarely matches in shade.
- Count skirting separately: one tile typically yields 3–4 skirting strips.
- Keep 2–3 labelled spares after laying — the future repair that matches.
Counting tiles looks like the easy part of a tiling job, and it is — right up to the moment a floor finishes two tiles short and the shop’s next batch is half a shade lighter. The counting is division; the craft is wastage and batches.
Tiles per square metre, by size
Divide your area by one tile’s area (the calculator adds the joint width for exactness):
- 300 × 300 mm (1 × 1 ft): ≈ 11.1 per m² — about 103 per 100 sq.ft
- 300 × 600 mm: ≈ 5.6 per m² — about 52 per 100 sq.ft
- 400 × 400 mm: ≈ 6.3 per m² — about 58 per 100 sq.ft
- 600 × 600 mm (2 × 2 ft): ≈ 2.8 per m² — about 26 per 100 sq.ft
- 600 × 1200 mm: ≈ 1.4 per m² — about 13 per 100 sq.ft
- 800 × 800 mm: ≈ 1.6 per m² — about 15 per 100 sq.ft
Wastage is a property of the layout, not luck
- Straight lay in an open room: cuts land on two walls and offcuts often reuse — 5% covers it.
- Rooms with columns, niches and doorways: more cuts, fewer reusable offcuts — 10%.
- Diagonal, herringbone, or any pattern: every perimeter tile is an angled cut that rarely reuses — 15%.
- Large-format in small rooms: a 1200 mm tile in a 7-foot bathroom is mostly cuts; wastage can pass 20%, and a smaller tile is sometimes the cheaper floor.
Worked example: a 10 × 12 ft bedroom in 600 × 600
- 120 sq.ft = 11.15 m² → with 10% wastage ≈ 12.3 m².
- 12.3 ÷ 0.36 m² per tile ≈ 34.1 → 35 tiles.
- At 4 tiles per box → 9 boxes (36 tiles). The 36th is your labelled spare.
The batch rule
Shade and calibration are printed on every box because they vary between production runs. A floor laid from one batch is uniform; a floor topped up from a different batch has a visible patch that no grout colour rescues. Order the full quantity — wastage included — in one lot, ask the dealer to pull one batch number, and check boxes for transit chips before signing.
What tiles alone don’t tell you
A tile order is a third of the floor. The same room needs adhesive (which scales with tile size — large format needs double the bed) and grout (which scales the opposite way — small tiles need more). The Tiles, Adhesive and Grout calculators under Tools & Support run all three from the same room dimensions, which is how the three orders arrive matched.
