Wall Tile Calculator — Tiles, Adhesive & Grout Needed

It depends on tile size. For 300x600mm tiles you need approximately 5.6 tiles per m², for 250x400mm about 10 per m², and for 100x200mm metro tiles about 50 per m². Always add 10% for straight or brick bond patterns and 15% for herringbone to cover cuts and breakages.

For bathroom walls, use a flexible powder adhesive (such as Weber or Mapei) rated C2 or higher. Flexible adhesive handles the moisture and temperature changes in bathrooms. For plasterboard substrates, a flexible powder adhesive is essential. Ready-mixed adhesive is only suitable for small ceramic tiles on dry walls. See our Tile Adhesive Calculator for exact quantities.

BS 5385-1:2018 sets the minimum joint width by tile size: tiles under 0.1 m² with no side over 600mm (e.g. metro and most square wall tiles) need a minimum 2mm joint, while tiles 0.1–1 m² with no side over 1200mm — which includes the popular 300×600mm format (0.18 m²) — need a minimum 3mm joint. Metro tiles are often laid tight, at the 2mm band minimum. Anything below 2mm is under the floor of the lowest band in the standard, so the calculator no longer offers it: a sub-2mm joint cannot be reliably filled and compacted, and it leaves no room for dimensional tolerance in the tiles themselves. Use our Grout Calculator for precise grout quantities.

You do not need to tile behind a bath panel, but you should tile at least one tile row above the bath rim to waterproof the splash zone. Building Regulations do not specifically require tiling, but best practice is to tile at least 300mm above any fitting where water may splash. Many tilers tile the full wall for a cleaner finish.

Allow 10% waste for straight or brick bond laying patterns, and 15% for herringbone or diagonal patterns. Herringbone requires more cuts, especially at edges. If you have many obstacles (windows, niches, pipe boxings), consider adding an extra 5% on top. It is always better to have spare tiles than to run short mid-job.