Tile Thinset Calculator
Calculate thinset mortar bags for your tile project. Enter area, trowel size, and bag coverage to get the right amount of tile adhesive.
Tile Grout Calculator
Calculate grout needed for your tile project. Enter tile size, grout line width, and area to get accurate pounds or bags of grout required.
in
in
in
in
sq ft
lbs
Grout Needed⧉
7.2 lbs
Including 10% waste
Bags Needed⧉
1
25 lb bags
Planning notes, formulas, and examples
About the Tile Grout Calculator
Grout fills the joints between tiles, providing structural stability, preventing moisture penetration, and completing the aesthetic of your tile installation. Calculating grout precisely is essential because too little means you run out mid-wall, and different tile sizes and grout line widths require dramatically different amounts of grout.
This tile grout calculator uses a standard industry formula based on tile dimensions, grout joint width, tile thickness, and the area to be grouted. The result is given in pounds and converted to bags. Grout consumption depends heavily on joint width — doubling the grout line width more than doubles the grout needed.
Sanded grout is used for joints 1/8” or wider; unsanded grout is for joints under 1/8”. Epoxy grout is used in wet areas and where stain resistance is critical. This calculator works for all grout types.
When This Page Helps
A 25-lb bag of grout covers anywhere from 50 to 300+ sq ft depending on tile size and joint width. Without proper calculation, you'll either buy too many bags or run out. This calculator gives you the exact bag count.
How to Use the Inputs
- Enter the tile width and length in inches.
- Enter the tile thickness in inches (usually 1/4” to 3/8”).
- Enter the grout joint width in inches (e.g., 1/8”, 3/16”, 1/4”).
- Enter the total area to grout in square feet.
- Enter the bag size (usually 10 or 25 lbs).
- Review the pounds of grout and number of bags.
Formula used
Volume Factor = ((TileW + TileL) × JointWidth × Depth) / (TileW × TileL)
Grout (lbs) = Area × 144 × Volume Factor × Density
Bags = ⌈Grout lbs / Bag Size⌉Example Calculation
Result: 2 bags (25 lb)
For 12”×12” tiles at 3/8” thick with 1/8” grout joint over 100 sq ft: the grout volume factor is low because the tile is large and joint narrow. Approximately 32 lbs of grout needed = 2 bags of 25 lbs.
Tips & Best Practices
- Sanded grout for joints 1/8” or wider; unsanded for narrower joints.
- Epoxy grout is stain-proof and ideal for kitchen countertops and showers.
- Mix only as much grout as you can apply in 20–30 minutes.
- Work grout diagonally across tile to fill joints completely.
- Wipe excess grout from tile faces within 10–15 minutes.
- Seal cement-based grout after curing to prevent staining.
- Grout color can change the entire look — test a sample first.
Grout Types Explained
Cement-based sanded grout is the most common and affordable. Cement-based unsanded grout is smooth and used for narrow joints and polished tile. Epoxy grout (two-part resin) is waterproof, stain-proof, and chemical-resistant but harder to apply. Urethane grout is pre-mixed and flexible.
Grout Joint Width Standards
Nominal 1/16” is the narrowest practical joint (rectified tile only). 1/8” is the most common for wall tiles and subway tiles. 3/16” is standard for floor tiles. 1/4” and wider is used for rustic, handmade, or natural stone tiles.
Mixing and Application
Mix grout to a thick peanut-butter consistency. Let it slake (rest) for 5–10 minutes, then remix before use. Apply with a rubber grout float at 45° to the joints. Work in 10–20 sq ft sections to prevent premature hardening.
Cleanup and Curing
Wipe haze with a damp sponge within 15 minutes of application. Use a clean bucket of water and rinse the sponge frequently. Final polish with a dry cloth after initial cleaning. Mist-cure cement grout for the first 72 hours.
Sources & Methodology
Last updated:
Frequently Asked Questions
It depends on tile size and joint width. Small tiles (2”) with 1/8” joints need ~1 lb/sq ft. Large tiles (12”) with 1/8” joints need ~0.3 lb/sq ft. Wider joints increase consumption significantly.
Sanded grout for joints 1/8” and wider — the sand prevents shrinkage cracking. Unsanded for joints under 1/8” — sand won't fit in narrow joints and can scratch polished tile. Epoxy grout works for all joint widths.
Grout is ready for light use in 24 hours. Full cure takes 28 days. During the first 72 hours, mist with water periodically to slow curing and increase strength. Don't seal grout until it's fully cured.
Yes, seal cement-based grout after it fully cures (28 days). Grout sealer repels water and stains. Reapply annually in heavy-use areas. Epoxy grout does not need sealing.
Match grout to tile color for a unified appearance. Contrast grout color to highlight tile patterns. Dark grout hides dirt but can stain light tile. Test grout color samples before committing.
Buy 10–15% more than calculated. Grout spreads unevenly, and some is lost during cleanup. You may also need grout for touch-ups later. Unopened bags store well for future repairs.
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