How many tiles do you need for a floor or a wall?
Updated October 2, 2026
Running short of tiles is worse than for most materials: a later order may come from another batch with a slightly different shade. The calculation takes the area to cover, the space taken by one tile with its joint, and a waste margin for cuts and breakage.
1. The area to tile
Measure in metres:
- Floor: length × width; split an L-shaped room into rectangles and add them up.
- Wall: width × height to tile, minus doors and windows.
- Do not deduct small obstacles (a pipe, a toilet base): the cuts around them consume tiles anyway.
2. Tiles per square metre and waste
One tile covers (length + joint) × (width + joint). A 60 × 60 cm tile with a 3 mm joint covers 0.603 × 0.603 ≈ 0.364 m².
Add a waste margin for cuts and breakage: about 5 to 10 % for a straight layout in a simple room, 10 to 15 % for a diagonal or herringbone layout, many cuts or very large formats.
Worked example: a 4.2 × 3.5 m room
60 × 60 cm tiles, 3 mm joints, 10 % waste:
- Area: 4.2 × 3.5 = 14.7 m²; with 10 %, 16.17 m².
- Tiles: 16.17 ÷ 0.3636 = 44.5, so 45 tiles.
- In boxes of 4 tiles (1.44 m²): 45 ÷ 4 = 11.25, so 12 boxes.
Before ordering
Check that all boxes carry the same batch (shade) number, and keep one or two spare tiles for future repairs. Adhesive and grout quantities depend on the product and the trowel: read them on the bags.
An uneven floor first needs levelling: the screed calculator gives the volume and the cement and sand. For the walls you are painting, use the paint calculator.
General information, checked at the date shown. It does not replace advice from a professional for your situation.