Question 1

How much extra should I order for wastage?

Accepted Answer

A simple rectangular room laid in a straight grid typically needs about 5–10% extra for cuts and breakage. Diagonal, herringbone, or other patterned layouts, rooms with lots of corners or fixtures, or larger tiles that are harder to cut precisely usually need 12–15% or more — order on the higher end if you are unsure.

Question 2

Should I order tiles by the piece or by the box?

Accepted Answer

Most suppliers sell tile only by the full box, and mixing dye lots between boxes bought at different times can create visible color variation. This tool rounds up to full boxes so you buy enough from the same batch in one order, with any leftover kept as a spare for future repairs.

Question 3

Does grout width affect the tile count?

Accepted Answer

Grout lines take up a small amount of floor area, but the effect on tile count is minor compared to wastage from cuts — which is why the wastage percentage already provides enough buffer for typical grout widths of a few millimeters. For very wide grout joints (over 10mm) on small tiles, consider using a slightly higher wastage percentage.

Question 4

What if my room is not a simple rectangle?

Accepted Answer

For an L-shaped or irregular room, split it into rectangular sections, calculate each separately, and sum the tile and box counts — or run this calculator once using the total combined floor area in place of length × width.

Room area	20 sq m
Single tile area	0.36 sq m
Total tile area (incl. wastage)	22.32 sq m

Flooring & Tile Calculator

How the tile count is calculated

Common questions