Practical guide
How to Calculate Floor and Wall Tiles in m²
Measure floors and walls, subtract untiled areas and convert a tile estimate into complete boxes.
Updated 15 October 2026
Reviewed by the 99Tools team. Editorial and corrections policy.
Measure each surface
For floors, multiply room length by width. For a wall, multiply tiled width by tiled height. Add each distinct rectangle once. Use the same measurement unit throughout and convert square feet to m² by multiplying by 0.09290304.
Account for openings and cuts
Deduct only untiled areas. Small openings can still require cut tiles, so agree deductions and waste with your tiler. Diagonal layouts, borders and many corners can change the allowance; no single percentage guarantees enough material.
Calculate full boxes
Multiply net area by 1 plus waste percentage divided by 100. Divide by labelled m² per box and round up once to a full box count. For 20 m², 10% waste and 1.44 m² per box, order 16 boxes. Do not round the initial area-to-tile division before applying waste.
Floor tiles and wall tiles
The quantity formula does not prove product suitability. Check the specified use, substrate, slip requirements where applicable and installation instructions. A wall tile is not automatically suitable for a floor.
Use the related calculators
Apply the explanation above with your own figures. Open a calculator below, check every input and review the result assumptions before making a decision.
Frequently asked questions
How do I calculate tiles per square metre?
Divide 1 by the coverage of one tile in square metres. A 600 × 600 mm tile has a nominal face area of 0.36 m². Use supplier coverage when available, add your chosen waste once, then round up whole boxes.
Does the calculator add waste automatically for a pattern?
No. Enter one allowance agreed with your tiler for the actual layout, cuts and breakage. The example 10% is editable and is not a guarantee for every job.
Is this the CTM tile calculator?
No. 99Tools is independent. Use the exact product label or quote for tiles per box and square metres per box, including products bought from CTM.
Can I use square feet?
Yes. Select feet for surface dimensions and deductions. One square foot is exactly 0.09290304 m². Product dimensions remain in millimetres and box coverage in m².