Calculating how many wall tiles you need for a project starts by finding the square meterage of each wall.
Take a tape measure and measure the height (from floor to ceiling) and length (left to right) or cover each wall’s intended tile area. Once you have these measurements, multiple them together. E.g., 2.4m high x 4.7m long gives you a total square meterage of 11.28. Complete this process for each wall and then add all sums together.
You will need to subtract the area used by doors and windows, which you can do using the same calculation method.
Importantly, allow for cuts and breakage, so add an additional 15% to the total sum. Then, you will have the total square meterage of all walls, allowing for waste.
You can then determine how many tiles you need by dividing the total square meterage by the number of tiles per square metre. The box the tiles come in usually state this, or you can work it out with another calculation.
If the tile is 30cmx60xcm, you would enter 10,000 on a calculator, then divide it by 30, then divide again by 60. This size tile will give you the answer, 5.5555. So, 5.55 tiles per square metre.