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Tile Calculator

Calculate how many tiles, adhesive, and grout you need for floors or walls.

Part of:Flooring hub
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How to Use This Calculator

What this tile calculator does

This tile calculator works out how many tiles you need for a floor or wall, allowing for the grout joint and a cutting waste percentage. Enter the area and tile size and it returns the tile count, area covered and boxes to buy – for ceramic, porcelain, natural stone or mosaic, in metric or imperial.

How to use it

  1. Enter the area to be tiled (length × width).
  2. Enter your tile dimensions.
  3. Set the grout joint width and a waste allowance.

Recommended waste by layout

LayoutWaste
Straight / grid10%
Diagonal15%
Herringbone / complex20%

Worked example

A floor 4 m × 3 m = 12 m². With 300×300 mm tiles (0.09 m² each) that's about 134 tiles; add 10% waste → ~148 tiles. Always round up to full boxes and keep spares for future repairs.

Tips

  • Wall tile joints are usually 2–3 mm; floor tile joints 3–5 mm.
  • Buy all tiles from the same batch (shade/lot number) so colours match.
  • Large-format tiles need a flatter substrate and more adhesive.

Common Questions

How many tiles per square metre?

It depends on tile size. For 300×300 mm tiles, you need about 11 per m². For 600×600 mm, about 3 per m².

How much waste should I allow?

10% for straight layouts, 15% for diagonal, and up to 20% for L-shaped rooms or complex patterns.

How much tile adhesive do I need?

Roughly 4-5 kg per square metre for standard tiles, or 1 lb per square foot.

Where should I start when tiling a wall or floor?

Find the centre of the area and set out from there so cut tiles fall evenly at the edges. On walls, work up from a level batten on the lowest full row; on floors, dry-lay a row first to check the layout.

What size tile spacers should I use?

Use 2–3 mm spacers for wall tiles and 3–5 mm for floor tiles. Large-format and rectified tiles can take narrower joints, while rustic or handmade tiles usually need wider ones.

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Further Reading