How many tiles do I need?

Divide the area you are tiling by the area of one tile, then add a waste allowance for cuts and breakages. The calculator does this for you once you enter the area and the tile size, and a typical waste allowance is 10%.

How much waste should I allow?

Around 10% is normal for a simple layout. Allow more, up to 15% or 20%, for diagonal patterns, lots of cuts, or large format tiles, and keep a few spares for future repairs.

How do I work out the tile size in square metres?

Multiply the tile width by its height in metres. A 300 by 300 mm tile is 0.3 by 0.3, which is 0.09 square metres, so it takes about 11 tiles to cover a square metre. The calculator handles this from the millimetre sizes you enter.

Tile Calculator

This tile calculator works out how many tiles you need to buy for a floor or wall, so you order the right amount without running short mid-job or paying for tiles you never use. You enter the area you are tiling in square metres, the width and height of a single tile in millimetres, and a waste allowance as a percentage to cover cuts and the odd breakage. The calculator works out the area covered by one tile, divides your total area by that to get the base number of tiles needed, then adds your waste percentage and rounds up to a whole tile, since suppliers do not sell part tiles. The result shows the total tiles to buy including waste, plus a breakdown of the tiles needed for the area alone and the tiles per square metre for your chosen size, so you can check the maths or compare tile sizes before buying. A waste allowance of around 10% suits a straightforward layout with tiles laid square to the walls, while diagonal patterns, awkwardly shaped rooms, and large format tiles cut more wastefully and are worth budgeting 15 to 20% for. It is also worth keeping a few spare tiles aside for future repairs. Treat the figure as a solid ordering guide rather than an exact count, since real wastage depends on your layout and cutting skill.

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Area to tile (m²)

Tile width (mm)

Tile height (mm)

Waste

0 tiles

to buy, including waste

Tiles for the area0

Tiles per m²0

How it works

One tile covers its width times its height. Divide the area you are tiling by that to get the base number of tiles, then add the waste percentage for cuts and breakages. The calculator rounds up to whole tiles, since you cannot buy part of one.

Worked example

For 12 square metres with 300 by 300 mm tiles, each tile covers 0.09 square metres, so you need about 134 tiles for the area. Adding 10% waste takes it to around 148 tiles to buy.

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