Tile Calculator
Estimate the total number of tiles needed to cover a floor, roof, wall, or any other surface.
Surface area
Tile size
Tiles needed:
With 10% waste:
Tile area:
Surface area:
Why the grout gap increases tile count
Grout lines between tiles mean each tile effectively "occupies" slightly more surface area than its bare dimensions suggest — the grout gap percentage inflates each tile's effective footprint before dividing it into the total surface area, so the final tile count accounts for the space grout lines take up rather than assuming tiles fit together with zero gap.
Frequently asked questions
Why is there both a "grout gap" adjustment and a separate 10% waste figure? They account for different things — the grout gap adjusts each tile's effective coverage area, while the waste factor covers cutting losses, breakage, and future repairs; both increase the final purchase quantity but for different reasons.
Should I round up when buying tiles? Yes — always round up to a whole number of tiles (or full boxes, if sold that way), and buying with the waste factor included helps ensure you don't run short mid-installation or need to source a matching dye lot later.
Does tile shape affect this calculation? This calculator assumes rectangular tiles laid in a simple grid — more complex layouts (herringbone, diagonal, mixed sizes) typically require a higher waste allowance than the standard 10% used here.