About this calculator
Grout depends on tile size and joint width far more than on area. This works it out from the joint volume.
How it’s calculated
Grout volume = area × (tile length + tile width) ÷ (tile length × tile width) × joint width × joint depth. Weight = volume × about 1.6 kg/L.
Worked example
With these inputs:
- Measure by
- Length × width
- Length
- 4.5 m
- Width
- 3.6 m
- Tile width
- 300 mm
- Tile length
- 300 mm
- Tile thickness (joint depth)
- 8 mm
- Joint width
- 3 mm
- Bag size
- 5 kg
- Waste allowance
- 10%
the result is:
- Grout needed
- 4.6 kg
- Joint volume
- 3 L
Tips from the trade
- Small mosaics use several times more grout per area than large tiles.
- Epoxy grout is denser. Increase the weight by about 15%.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and the Building Regulations before ordering.