Tile Grout Calculator
How It Works
Grout fills the joints between tiles, providing a finished look and preventing moisture from getting underneath. The amount of grout needed depends on tile size, joint width, tile thickness, and total area. Smaller tiles and wider joints require significantly more grout.
Joint width recommendations vary by tile size: large format tiles (12 inches and up) typically use 1/8-inch joints, medium tiles (6-12 inches) use 1/8 to 3/16 inch, and small tiles (under 6 inches) and mosaics use 1/16 to 1/8 inch. Wider joints require more grout and take longer to cure.
Always buy 10% extra grout to account for waste during mixing and application. Sanded grout is used for joints wider than 1/8 inch, while unsanded grout is used for thinner joints and polished stone tiles that could be scratched by sand particles.
Frequently Asked Questions
How much grout do I need for 100 sq ft of 12x12 tile?
With 1/8-inch joints and 3/8-inch thick tiles, 100 sq ft of 12x12 tile needs approximately 10-12 lbs of grout, or about half a 25-lb bag. Smaller tiles need significantly more grout.
Sanded vs unsanded grout — which should I use?
Use sanded grout for joints 1/8 inch and wider. Use unsanded grout for joints smaller than 1/8 inch and for polished marble or other soft stones. Sanded grout is stronger and resists cracking in wider joints.
How long does grout take to dry?
Grout is typically ready for light use in 24-48 hours. Full curing takes 7-28 days depending on the product and conditions. Do not seal grout until it has fully cured. Avoid heavy moisture for the first 72 hours.
Should I seal grout?
Yes, cement-based grout should be sealed after curing (7-28 days) to prevent staining and moisture absorption. Epoxy grout does not need sealing. Reapply sealer every 1-2 years depending on wear.