Tile Calculator
Work out how many tiles – and boxes – you need for a floor, wall or splashback.
Result
Enter the area and tile size.
How the tile count is worked out
Each tile covers its own size plus one grout joint in each direction. The area is divided by that, the spare percentage is added, and the result is rounded up to whole tiles (and whole boxes if you enter the box quantity).
Example: a 2 m × 1.5 m floor (3 m²) with 300 × 600 mm tiles and 3 mm joints needs 17 tiles before spares and 19 with 10% extra – 4 boxes of 6.
Buy all your tiles from the same batch, as colours can vary slightly between batches.
Frequently asked questions
How much spare should I allow?
About 10% is the usual rule of thumb. Allow 15–20% for intricate patterns, rooms with lots of cuts, if you’re new to tiling, or if you’d like spares for future repairs.
Do grout joints make a difference?
Slightly: joints spread the tiles out, so you need a few fewer. Floor tiles typically use 3–5 mm joints (BS 5385 guidance is at least 3 mm on floors) and wall tiles 2–3 mm.
Should I subtract windows and doors?
For walls, measure each tiled area separately and leave out large openings. Small gaps are better left in – the extra tiles cover cutting waste.
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