π§ Grout Calculator
Calculate grout needed based on tile size, joint width, and area.
Grout Bags Needed
How to Use This Calculator
Enter the tiled area length and width in feet, then set your tile dimensions in inches, the joint width, and tile thickness. Choose the bag size for your specific grout product and set the waste percentage. The calculator tells you how many pounds of grout you need and how many bags to buy.
Measure the tiled area length and width in feet. For walls, measure each wall face separately and add them together.
Enter tile dimensions in inches. Use the actual tile size, not the nominal size. A "12x12" tile is usually 11.75 inches, and that difference adds up over a large area.
Choose the joint width. Use 1/8 inch for most floor tiles 6 inches or larger. Use 3/16 or 1/4 inch for larger tiles or outdoor applications where more movement is expected.
Set tile thickness. Most standard ceramic tiles are 5/16 inch thick. Porcelain tiles tend to be slightly thicker. Check the product specs or measure an actual tile.
Grout Quantity Formula
Grout quantity changes significantly with tile size and joint width. A 12x12 tile with a 3/16-inch joint needs about 0.18 lbs per square foot. A 4x4 tile with the same joint width needs about 0.54 lbs per square foot, three times as much, because small tiles have far more total joint length per area.
Example Projects
Tips for Your Project
Use sanded grout for joints 1/8 inch or wider and unsanded grout for joints narrower than 1/8 inch. Sanded grout is stronger and resists shrinking in wider joints. Using unsanded grout in a wide joint often leads to cracking as the grout cures and shrinks. The bag label will specify the joint width range for each product.
Mix grout to a peanut butter consistency and let it slake (rest) for 10 minutes before use. Do not add extra water to thin it. Apply grout with a rubber float held at a 45-degree angle, working it diagonally across the joints. Remove excess grout from the tile face within 20 to 30 minutes using a damp sponge. Wait 24 hours before walking on floor tile and 72 hours before getting it wet.
Frequently Asked Questions
How much grout do I need per square foot?
It depends on tile size and joint width. Larger tiles with narrow joints need less grout; smaller tiles with wide joints need more. Typical range: 0.1β1.5 lbs/sq ft.
What is the difference between sanded and unsanded grout?
Sanded grout contains sand for joints 1/8" or wider β it provides better strength and crack resistance. Unsanded grout is for joints narrower than 1/8".
How much does one bag of grout cover?
A 25 lb bag typically covers 50β200 sq ft depending on tile size and joint width. Our formula gives an accurate estimate per your specific project.
Should I add extra grout?
Add 10β15% extra. Grout waste occurs from mixing losses, application loss, and needing to do touch-ups. Always buy from the same batch for color consistency.
Can I use leftover grout later?
Dry/powdered grout has a shelf life of ~1 year in a sealed container. Mixed grout has a pot life of ~30β60 minutes and cannot be saved.