Grout Calculator

Grout quantity depends on tile size, grout line width, and tile thickness. For example, 12x12 inch tiles with 1/8 inch grout lines typically need about 0.5-0.75 lbs of grout per square foot. Our calculator provides exact estimates based on your specific tile dimensions.

Use sanded grout for grout lines 1/8 inch (3mm) or wider. Use unsanded grout for grout lines less than 1/8 inch. Sanded grout contains fine sand particles that provide strength and prevent shrinking in wider joints. Unsanded grout flows better into narrow spaces and is less likely to scratch polished stone or glass tiles.

Hexagon tiles require more grout than square tiles of similar size because they have 6 sides instead of 4. When using our calculator, select the "Hexagon Tiles" option and enter the flat-to-flat width measurement (the distance across the hexagon through its center). The calculator automatically accounts for hexagon geometry and calculates the correct grout quantity.

We recommend buying 10-15% extra grout to account for waste during mixing, material left in the bucket, uneven grout lines, and future touch-ups or repairs. Our calculator includes an adjustable overage option (0%, 5%, 10%, or 15%) so you can plan accordingly. It's always better to have a little extra than to run out mid-project and risk color mismatches between batches.

Grout coverage refers to how much area a given amount of grout will fill. The industry-standard formula calculates the total volume of grout joints by multiplying the total grout line length by the joint width and depth (tile thickness). This volume is then converted to weight using the grout's density. Sanded grout is denser (~104 lbs/ft³) than unsanded grout (~86 lbs/ft³), which is why you need slightly more sanded grout by weight for the same project.