Use the free Grout Calculator UK on ToolVexa to estimate grout for a tiled area. Enter the tile size, joint width and depth, and area, press Calculate, and your result appears straight away, including a 10% waste allowance.
How to Use
Enter the tile length and width in centimetres, the joint width and depth in millimetres, and the area in square metres. Press Calculate to see the grout needed in kilograms.
Formula in Plain Words
Joint length per square metre comes from the tile size. Multiply it by joint width, joint depth and area to get the grout volume, convert it to kilograms at a typical density, then add 10% for waste and spills.
Worked Example
For 30 cm by 30 cm tiles, a 3 mm joint, a 6 mm depth and 10 m², the calculator gives 2.11 kg of grout with the waste allowance.
FAQs
Why add a waste allowance? Grout is lost in mixing, spills and cleaning, so a small allowance avoids running short part way through a job.
Does grout type change the result? Density varies by product, so always check the bag coverage for your chosen grout and buy at least the estimated amount.
Should I round up? Yes, round up to the nearest bag size sold, especially for small areas.