Tile Count Waste
Calculator

It divides the floor or wall area to be tiled by the area of a single tile (accounting for the tile's actual dimensions, since grout lines add a small amount to the effective spacing), giving the theoretical minimum tile count before any waste allowance.

Tiles need to be cut to fit at walls, corners, and around fixtures, and those cut pieces are often unusable elsewhere — plus tiles break during handling and cutting — so a waste factor (commonly 10% for simple layouts) ensures you don't run out mid-installation.

Yes — diagonal (45-degree) layouts generally need a higher waste allowance, often 15-20%, because more tiles require angled cuts at the room's perimeter, producing more offcuts and reducing how much of each cut tile can be reused elsewhere.

Yes — tile is sold by the box (a fixed number of tiles or square footage per box), so round the total needed (including waste allowance) up to the next full box, since a partial box typically costs the same as a full one and matching dye lots later can be difficult.

Tile color and shade can vary slightly between production batches (dye lots), so buying slightly more than the calculated need from the same lot — enough to cover future repairs or replacements — avoids a visible mismatch if a tile cracks years later and the original product is no longer manufactured.