How the tile calculation works

The calculator divides the total surface area by the face area of one tile, adds the selected waste percentage and rounds up to a whole tile.

Wall and floor tiles

The same area calculation can be used for rectangular walls and floors. For multiple surfaces, calculate each one and add the quantities together.

This is an area-based estimate. Exact tile counts can differ because of room shape, grout joints, layout, cuts, pattern matching and tile breakage.

Frequently asked questions

Does grout-joint width affect the result?

It can affect the exact layout, but for purchasing quantities the waste allowance usually provides a more useful practical buffer.

Should I keep spare tiles?

Keeping a few spare tiles can be useful for future repairs, especially where the same batch may be hard to source later.

How the tile count is produced

The calculator divides the surface area by the face area of one tile, rounds up to complete tiles and adds the selected waste allowance. Enter the tile's actual dimensions in millimetres. If the manufacturer sells tiles by the box, compare the final tile quantity with the number of tiles or square metres supplied per box and round up to a complete box.

Layout drives cutting waste

A straight grid in a rectangular room usually creates fewer offcuts than diagonal, herringbone or heavily patterned layouts. Niches, window reveals, columns and multiple corners also increase cutting. Before ordering, establish a setting-out line so very narrow cuts at opposite edges can be avoided where possible.

Do joints change the calculation?

Grout joints slightly increase the area covered by each tile module, but for purchasing it is normally safer to base the calculation on tile face dimensions and a sensible waste allowance rather than reduce the count for joints. Adhesive, grout, trims, membranes and backer boards are separate materials. For natural stone or shade-sensitive products, keeping spare matching tiles can also be useful for later repairs.