What this calculator does
Tile grout needed works out weight of grout for a tiled area, from tile size and joint dimensions. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaGrout area share = 1 − (l×w)/((l+g)×(w+g)); grout volume = surface area × grout share × joint depth; weight = volume × density
The inputs explained
| Field | What to enter |
|---|---|
| Area to tile (m²) | A number, measured in m². Starts at 20. |
| Tile length (mm) | A number, measured in mm. Starts at 300. |
| Tile width (mm) | A number, measured in mm. Starts at 300. |
| Joint (gap) width (mm) | A number, measured in mm. Starts at 3. |
| Joint depth (≈ tile thickness) (mm) | A number, measured in mm. Starts at 8. |
| Grout density (kg/m³) | A number, measured in kg/m³. Starts at 1600. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with area to tile
Every other input is held at the calculator’s starting values while area to tile varies. Select any row to load that scenario into the calculator.