Tile Calculator

For a rectangular surface, start with the area:

Area = Length × Width

Tile quantity then comes from the tile size, the grout joint, the layout and the extra-material allowance you choose. For a simple grid, each dimension is counted on its own:

Tiles Along Dimension = ceil((Surface + Joint) ÷ (Tile + Joint))

Multiply the rows by the columns for the grid layout count, then apply your waste allowance.

Tile face area uses the same multiplication as any rectangle:

Tile Area = Tile Length × Tile Width

Units are converted consistently, so a 300 × 600 mm tile is 0.18 m² whether you work in millimetres, inches or feet. Package coverage may differ slightly from nominal tile dimensions, so use the manufacturer's stated carton coverage for purchasing where available.

The joint width changes the effective tile module, which changes how many rows and columns fit on the surface, and it also affects how much grout the job uses.

Because tiles share their internal joints, there is one fewer joint than tiles across a dimension. That is why the joint appears on both sides of the division rather than being added after every tile.

Use the grout-joint width specified for your tile, product and layout. Joint guidance varies by tile and pattern, so no width is recommended here.

An area-based count divides the tiled area by the tile face area. It is ideal for irregular surfaces and several sections, but it can undercount because edge tiles are cut and the offcuts are not always reusable.

For a simple rectangle the calculator also builds the grid layout and shows both figures, then uses the larger one as the base quantity so the count is never optimistic. Both numbers stay visible.

Complex tile patterns can increase cuts and waste. Adjust the waste allowance based on the tile manufacturer, pattern and installer guidance. For diagonal and patterned layouts the quantity is area-based, because an exact cut layout is not simulated.

Extra tile may be needed for edge cuts, breakage, pattern alignment and future repairs.

Extra tile may be needed for edge cuts, breakage, pattern alignment and future repairs. Around 10% is commonly used as a planning example, but actual requirements vary by tile, layout and installer — the allowance stays editable and no hidden allowance is added.

Recommended Tiles = ceil(Base Tiles × (1 + Waste%))

Tile is normally sold by the carton, so the count rounds up to whole boxes:

Boxes = ceil(Required Area ÷ Coverage Per Box)

or, when the packaging lists a piece count:

Boxes = ceil(Required Tiles ÷ Tiles Per Box)

If you enter both, the calculator shows both checks. The manufacturer's stated coverage governs the purchase quantity, because nominal tile sizes and actual packaging can differ — and neither figure silently overrides the other.

Mosaic products are usually sold by sheet or carton. Use the actual coverage per sheet or box rather than inferring a count from individual mosaic chips.

Sheets = ceil(Required Area ÷ Coverage Per Sheet)

The required area already includes your allowance, so the waste is never applied twice. Enter sheets per box to convert the result into cartons.

Split an irregular surface into simple rectangles, calculate each one and add the results together. Multiple Areas mode does exactly this, and each rectangle gets its own grid layout so edge tiles are not lost in an averaged shape.

For walls, only subtract openings where tile will not be installed — a window, door, cabinet run or fireplace opening you have measured yourself.

Grout coverage depends on tile dimensions, joint width, tile thickness, product and packaging. Enter the coverage from the grout manufacturer's chart or package — BuildCalcWorks does not apply a generic grout formula.

Grout Packages = ceil(Net Tiled Area ÷ Coverage Per Package)

A dedicated Grout Calculator is planned and will use the same tiled-area engine. Until then, the optional grout section here works from the coverage you enter.

Adhesive and thin-set coverage varies by product, trowel size and substrate. Enter the coverage stated on the bag or container.

Optional material estimate from the coverage you enter. Whether backer board or underlayment is required is not determined here. Backer board can carry its own allowance, kept separate from the tile allowance.

Tile can be priced per box, per tile or per square foot or square meter — one pricing method at a time, and the method is always stated in the result. When boxes are calculated, a per-area price is applied to the purchased coverage, so the figure reflects what is actually bought.

Optional grout, adhesive, backer board and border/accent costs can be added. Material estimate only. Labor, demolition, substrate repair, waterproofing systems, delivery and tax are excluded unless you enter them as a custom cost.

This calculator estimates tile material quantities from the dimensions and product data you enter. It does not determine installation requirements, substrate preparation, waterproofing, product suitability or code compliance.

How BuildCalcWorks calculations are created →