Tile Calculator
Tiles needed by floor/wall area, tile size, and wastage allowance
Frequently Asked Questions
Tile quantity estimation combines floor or wall area, individual tile dimensions, and a wastage allowance that varies significantly by layout pattern and room shape — treating tile wastage as a fixed percentage regardless of layout is one of the most common ways contractors and DIY owners under-order.
Why wastage percentage isn't one-size-fits-all
A straightforward straight-lay pattern in a large, rectangular room typically needs around 10% wastage to cover cutting, breakage, and future replacement stock. But a diagonal layout, a room with many corners and cuts (bathrooms especially), or an irregular floor plan can push real-world wastage to 15% or more, since diagonal cuts and tight corners produce more unusable offcuts per tile than a simple straight run along a rectangular wall. Tile size also matters independently of layout: larger tiles generally waste more material per cut (since a cut-off piece from a large tile is a bigger absolute loss) even at the same wastage percentage.
A worked example
The identical floor area tiled in a straight-lay pattern versus a diagonal pattern needs meaningfully different total tile counts once wastage is factored in — ordering based on the straight-lay wastage assumption for a diagonal job risks running short mid-installation, which usually means a delay waiting for a matching batch (tile dye lots can vary between production runs) rather than a same-day top-up.
How this connects to your other construction planning
Tiling is typically one of the later finishing steps in a build — for the overall finishing-stage budget across paint, tile, and other final-touch materials together, see the Construction Cost Calculator. If the same room also needs a plastered surface underneath before tiling (walls rather than floors), the Plaster Calculator handles that earlier step.
Common mistakes
Using a flat 10% wastage default regardless of layout pattern or room shape is the most common estimating error — bump the wastage allowance up for diagonal layouts, bathrooms, and irregularly-shaped rooms, and consider ordering a small additional buffer of matching tiles for future repairs, since matching an exact dye lot months or years later is often impossible.