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Materials

How to calculate tile grout

Updated: 14 August 2026

Grout depends on the joint, the tile size, and the net area. Use the figure from the material list and buy whole packs.

Grout (fuga) is easy to under- or over-buy. The amount depends on joint width, tile format, and net tiled area — not on a random “one bag per bathroom.”

Worked idea

A floor 4.0 × 3.0 m (12 m²) with 600×600 mm tiles and a 3 mm joint needs far less grout than the same floor with 300×300 mm tiles and a 5 mm joint. Smaller tiles mean more joint length per square metre.

Steps

  1. Enter room size, tile size, and joint width in the tiling planner.
  2. Subtract openings so the area is net.
  3. Read grout on the material list. Adhesive and primer sit on gross (net × allowance) — see adhesive.
  4. Round up to whole packs of the brand you will buy.

If you change joint width from 2 mm to 4 mm, re-run the list before you shop — the grout line moves more than people expect.

Adhesive is covered in tile adhesive calculation.

Next: Adhesive · Piece counts · Download the app


See also