calcs.homes
calcs.homes
Enter your tile size, tile thickness, grout joint width, and the area, and this grout calculator estimates the pounds of grout and the bags to buy.
Estimate only — mixing waste, uneven substrates, and wide joints raise real grout use.
Grout fills the space between tiles, so the amount tracks with joint width, tile thickness (deeper joints hold more), and how many joints there are — smaller tiles pack more linear feet of joint into a square foot. We use the standard estimating formula, ((L + W) ÷ (L × W)) × joint width × tile thickness × a coverage constant, to get pounds per square foot, then multiply by your area.
This is a dry-weight estimate for a full, properly packed joint. You will use a little more if you are mixing small batches that stiffen before they are all used, or if the substrate is uneven so joint depth varies. Buy to the next whole bag and keep the leftover sealed for repairs.
Use sanded grout for joints 1/8 inch and wider — the sand keeps it from shrinking and cracking. Use unsanded for joints under 1/8 inch, and for polished stone that sand could scratch.
For 12x12 tile with 1/8-inch joints, roughly 8–12 pounds — one 25-lb bag with margin. Smaller tile or wider joints can double that.
Yes. A thicker tile makes a deeper joint that holds more grout, so 3/8-inch floor tile uses noticeably more grout per foot of joint than thin wall tile.