Grout Calculator
Calculate how much grout you need for tiling, based on area, tile size, joint width and joint depth.
How to use the grout calculator
- Enter the area to be tiled and grouted.
- Enter the tile size in centimeters (the calculator assumes square tiles).
- Enter the desired joint width and joint depth in millimeters — the joint depth often matches the tile thickness.
How the grout amount is calculated
The calculator uses a common industry formula for cement-based grout, based on the tile's perimeter relative to its area:
Where L and W are the tile dimensions in millimeters. The smaller the tiles, the more grout you'll need per square meter, since there are more and longer joints in total. Total consumption is found by multiplying the coverage per m² by the area.
Joint width and tile format drive consumption
Grout consumption depends on how much joint volume there is per square metre, and that follows from three things: the joint width, the joint depth — which is the tile thickness — and how many linear metres of joint there are. Small tiles produce many metres of joint per square metre and therefore high consumption, while large tiles produce few. Go from ten centimetre mosaic to sixty centimetre tiles and grout consumption falls dramatically even though the area is the same.
The type of grout should be chosen for the use, not just the colour. Cement-based grout is standard indoors, while epoxy grout resists chemicals and water better and is used in heavily loaded wet rooms or commercial kitchens. Epoxy is at the same time far less forgiving to work with, since it cures quickly and has to be washed off the tiles before it sets.
Frequently asked questions
Why does tile size affect grout consumption?
Smaller tiles give more joints per square meter, since the perimeter relative to the area increases the smaller the tile is. That's why you use more grout per m² with small tiles than with large ones.
Should I choose wide or narrow joints?
It depends on the tile type and style. Narrow joints (1–3 mm) give a more seamless look, while wider joints (4–8 mm) are common for natural stone or tiles with uneven edges, and better tolerate movement in the substrate.
What's the difference between grout and silicone sealant?
Grout (cement-based) is used in the flat joints between tiles, while silicone sealant is used in movement joints and corners, for example between floor and wall or around drains, where rigid joints crack easily.