Grout Coverage Calculator
Calculate the amount of grout needed for your tiling project based on tile dimensions, joint width, tile thickness, and total area.
Fill in the fields above and click Calculate.
Formula
Joint Factor (JF) = (Tile Width + Tile Height) / (Tile Width × Tile Height) [in⁻¹]
Grout Volume (ft³) = Area (ft²) × JF × Joint Width (in) × Tile Thickness (in) / 144
Grout Weight (lbs) = Grout Volume (ft³) × Grout Density (lbs/ft³)
Total Grout with Waste (lbs) = Grout Weight × (1 + Waste% / 100)
The Joint Factor accounts for the linear feet of joints per square foot of tile area. Dividing by 144 converts the joint cross-sectional area from in² to ft².
Assumptions & References
- Formula follows the Tile Council of North America (TCNA) Handbook standard grout coverage method.
- Default grout density of 100 lbs/ft³ is typical for sanded Portland-cement grout; unsanded grout is ~95 lbs/ft³.
- A 10% waste factor is the industry-standard minimum; increase to 15–20% for diagonal layouts or complex cuts.
- Tile dimensions and joint width must be entered in inches; area in square feet.
- Grout joint width should be ≥ 1/16 in (0.0625 in) and must be smaller than both tile dimensions.
- Typical tile thickness ranges from 1/4 in (mosaic) to 1/2 in (large-format porcelain).
- Results are estimates; always verify with your grout manufacturer's coverage chart.
- Reference: TCNA Handbook for Ceramic, Glass, and Stone Tile Installation; Ceramic Tile Institute of America (CTIOA).