Grout Calculator
Running out of grout mid-project means color-matching headaches and visible batch differences. This calculator determines exactly how much grout your tile installation needs based on tile dimensions, joint width, and coverage area, so you can buy the right amount in one trip.
Grout volume depends on the total length of joints per square foot (determined by tile size), the joint width, and the tile thickness (which sets the joint depth). Smaller tiles create more joints per square foot and therefore require more grout. A 2x2 mosaic uses roughly 4 times more grout than a 12x12 tile.
The calculator uses the formula: Joint Length per sq ft = (1/tile_width + 1/tile_length) x 144, then multiplies by joint width, tile thickness, and area. A 10% waste factor is automatically included for cleaning, overfill, and mixing losses.
Sanded grout is used for joints wider than 1/8 inch, while unsanded grout is used for joints 1/8 inch or narrower. Epoxy grout is more expensive but provides superior water and stain resistance for showers, countertops, and commercial applications. Always buy all your grout at once from the same lot number to ensure consistent color.