What this tool does
Estimates the weight of grout needed from tile area, tile size, joint width and depth, and grout density, using a thin-joint approximation.
How to use it
- Enter the tiled area in square metres.
- Enter one tile’s width and height in millimetres.
- Enter the joint width and depth in millimetres.
- Enter the grout density and run it.
Worked example
20 m² of 300×300 mm tiles with 3 mm joints 8 mm deep at a density of 1.6 needs about 5.12 kg.
Calculation method
Approximate grout mass
area*(length+width)/(length*width)*joint*depth*densityFrequently asked questions
- Why do smaller tiles need more grout?
- More tiles in the same area means more joint length. Mosaic tiles need far more grout than 300 mm tiles.
- Where do I find the density?
- In the manufacturer’s data sheet. The 1.6 default is illustrative and varies by product; adjust the depth to your tile thickness too.
What this tool does not cover
It is a thin-joint approximation, so wide joints increase the error. Mixing loss, cleaning loss, and irregular tile shapes are not reflected.