Tile Calculator

Tile Calculator online

Estimate how many tiles a floor or wall needs from the surface area and tile size, with a waste allowance matched to the laying pattern — so you buy enough in one dye lot without a pallet left over.

How it works

The tool divides surface area by the area of one tile, then adds waste: Tiles = Area / ((Length / 1000) × (Width / 1000)) × (1 + Waste / 100). At the defaults, one tile covers 0.300 × 0.300 = 0.09 m², so each square metre needs 1 / 0.09 = 11.11 tiles before waste. Grout joints are not subtracted — enter the actual tile dimensions and let the waste percentage absorb joints, edge cuts, and breakage.

Worked example

A 12 m² bathroom floor with 300 × 300 mm tiles and 10% waste for a straight lay: 12 / 0.09 = 133.33 tiles net, then 133.33 × 1.10 = 146.67, so 147 tiles to buy. For a 45-degree diagonal pattern use 15%: 133.33 × 1.15 = 153.33, so 154 tiles — seven more than the straight lay.

Units

Area is in square metres; tile dimensions are in millimetres (600 × 600 mm = 0.6 × 0.6 = 0.36 m² per tile). If your floor measures in feet, convert first: 12 m² is about 129.2 ft². Large-format tiles (600 × 600 mm and above) need flatter substrates and wider 3–5 mm grout joints, but the counting formula is unchanged.

Practical tips

• Use 10% waste for straight lays in square rooms, 12–15% for diagonal patterns, and 15–20% for herringbone or rooms with many niches.
• Keep tiles from one shade and calibre batch; check the codes on every box before leaving the store.
• Save 5–10 spare tiles from the same batch for future cracks or plumbing access — later batches rarely match exactly.
• This count covers tiles only; grout, adhesive, and whether the substrate can carry the tiled weight should be confirmed with the product data and a qualified installer.

Edge cases and limitations

• Buy whole boxes, keep a spare. The count is in individual tiles; divide by the tiles (or coverage) per box and always round up to full boxes. Keep one unopened box after the job — replacement tiles from a later production lot rarely match the shade exactly.
• Grout joints shave coverage. The count assumes tiles laid edge to edge. Wide joints on small tiles can eat several percent of coverage; the waste allowance normally absorbs it, but with 10 mm joints on 100 mm tiles, add a few percent extra.
• Patterns cost more than the example. Straight lay works at 10% waste; diagonal at 15%; herringbone and chevron can reach 20% because every border tile is cut. Match the allowance to the pattern, not to optimism.
• Mosaics come by the sheet. For mosaic, run the same area ÷ sheet-area calculation using the sheet size (often 300 × 300 mm) — the count you need is sheets, and sheets per box.
• Adhesive and grout are separate. This is a tile count only. Large-format tiles (600 mm and up) usually need back-buttering, which roughly doubles adhesive usage without changing the tile count.

Privacy and browser processing

The calculation runs entirely in your browser — your room dimensions are never uploaded.

Frequently asked questions

How many 300 × 300 mm tiles cover one square metre?

11.11 before waste, since 1 / (0.3 × 0.3) = 11.11. With 10% waste that is 11.11 × 1.10 = 12.22, so allow 13 tiles per square metre.

What waste percentage should I use?

10% suits a straight lay in a square room (147 tiles for the 12 m² example), while a diagonal lay needs about 15% (154 tiles). Small mosaics and L-shaped rooms with many cuts need the higher figure.

Do grout joints change the tile size I enter?

No. Enter the true tile size — 300 × 300, not 305 × 305 — because joints of 2–5 mm are absorbed in the waste allowance. Enlarging the tile size to account for joints would undercount the order.

How does tile size change the count?

Area per tile scales quadratically. The same 12 m² floor needs 12 / 0.09 = 133.33 tiles at 300 × 300 mm but only 12 / 0.36 = 33.33 tiles at 600 × 600 mm before waste — one quarter as many.

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