Tile Grout Quantity Calculator

About this calculator

Grout quantity depends on tile size, tile thickness and joint width — larger tiles need less grout per square meter because there are fewer joints, while thicker tiles or wider joints both increase the volume each joint holds. The standard trade formula multiplies the tiled area by the perimeter-to-area ratio of a single tile — (tile length plus tile width) divided by (tile length times tile width) — then by the joint width, the tile thickness and a grout density factor (roughly 1.6 for standard cementitious grout) to get the weight in kilograms.

Tilers and DIYers run this calculation before starting a job because buying grout by eyeballing the box size at the shop routinely leads to either running short mid-job with mismatched grout batches, or overbuying a product that has a shelf life and cannot simply be returned once opened.

This calculator takes your tiled area, tile size, tile thickness and joint width and returns the kilograms of grout needed, so you can buy the right amount in one trip.