Tile Grout Calculator
Enter the tile size, joint width, and area to get how many pounds of grout you need — works for floors, walls, and backsplashes.
Area & tile
You'll need
Estimate only — mix density and joint fill vary. Sanded grout for joints ≥1/8"; unsanded for smaller gaps.
How to calculate grout
Grout quantity depends on tile size, joint width, tile thickness, and area. Smaller tiles have more linear feet of joint per square foot and use significantly more grout. The formula is (tile width + tile height) ÷ (tile width × tile height) × joint width × tile depth × grout density, then multiplied by area. Use sanded grout for joints 1/8" or wider.
Get tile area from a LiDAR scan in seconds
ProBuildCalc turns your iPhone's LiDAR scanner into a job-site measuring kit — walk the space and it captures the square footage, material takeoff, and a blueprint automatically. No tape measure, no graph paper.
Grout calculator FAQ
- How much grout do I need per square foot?
- It depends on tile size and joint width. A 12×12 tile with a 1/8-inch joint uses roughly 0.15 lb of grout per sq ft. Smaller tiles have more joint area and use more grout per sq ft.
- Do I use sanded or unsanded grout?
- Use sanded grout for joints 1/8 inch or wider — the sand prevents cracking in wider gaps. Use unsanded (non-sanded) grout for joints under 1/8 inch, like on polished stone or glass tile where sand would scratch the surface.
- How much extra grout should I buy?
- Add about 10% to your calculated amount. Grout fills into the joints as you work and you'll waste some in mixing. Having a little left over is also useful for future repairs.
- How long does premixed grout vs dry-mix grout last?
- Dry-mix grout has a long shelf life if kept dry. Premixed (already wet) grout lasts 1–2 years unopened. Once mixed or opened, it should be used within 30–60 minutes.
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See also: estimating guides · ProBuildCalc by trade