Standard grout consumption formula
This calculation uses the standard formula widely adopted by grout manufacturers: Consumption (kg/m²) = [(A + B) ÷ (A × B)] × C × E × 1.6, where A and B are the tile dimensions in meters, C is the joint width in mm, E is the tile thickness in mm, and 1.6 is a grout density constant.
Example
A 60×60 cm tile, 8 mm thick, with a 3 mm joint, for 20 m²: consumption ≈ 0.53 kg/m² → about 10.6 kg of grout total.
Larger tiles = less grout
The larger the tile (large-format porcelain tile, for instance), the lower the grout consumption per m², since there are proportionally fewer joints.
Tip
Always buy a bit extra (5-10%) to cover touch-ups or application variations.
Frequently asked questions
Where does this formula come from?
It's the standard formula used by most grout manufacturers to estimate consumption per m².
Do larger tiles use less grout?
Yes, proportionally — larger tiles have fewer joints per m², reducing grout consumption.
Should I buy an extra margin?
Yes, 5-10% extra is recommended to cover application variations and touch-ups.
Does joint width affect the result much?
Yes, quite a bit — wider joints (e.g. 5mm vs 2mm) significantly increase grout consumption.