Formula and example
How it is calculated
kg/m² ≈ (tile length + width) / (length × width) × depth × joint width × consumption factor
Worked example
300 × 300 mm tile, 8 mm depth, 3 mm joint, factor 1.6: 0.256 kg/m².
Things to check
- The 1.6 example is the consumption factor in the Mapei formula used for this example; it is not a universal density for all products. Verify with the datasheet of the chosen grout.
- Approximate estimate for regular tile layouts. Actual joint depth, voids, rough surfaces and application waste may vary. A separate calculator is required for sealant in movement joints.
Frequently asked questions
Why is more grout needed for smaller tiles?
On the same tiled surface, there are more joints between smaller tiles. The formula approximates this specific joint length from the tile dimensions.
Is the 1.6 factor true for all grouts?
No. The example uses 1.6; other products must be calculated with the consumption factor and formula in their own datasheet.