Tile Calculator: How Much Tile, Grout & Thinset Do I Need?
Enter your area, pick a tile size and pattern, and the calculator estimates boxes of tile, bags of grout, and bags of thinset for a floor, wall, or shower install. Waste percentage adjusts automatically based on pattern and tile size so the estimate reflects what you actually need to buy.
Tile project details
Defaults work for a typical 12x12 floor. Adjust to match your project.
You need
Total area
0sq ft
Sq ft to purchase (with waste)
0sq ft
Boxes of tile
0boxes
Grout
0bag of 25 lb
Thinset
0bag of 50 lb
Estimated material cost
$0–$0
Don’t forget: Add 5 to 10 percent for backer board, sealant, spacers, and trim pieces , these are not included in the material estimate above.
How we calculated this
Tile tiers and what to expect
Typical price ranges for each tier matching the calculator. Buy what the calculator suggests, then keep one full box (and an extra bag of grout) after install for future repairs.
Budget: Budget ceramic tile at $1–$3 / sq ft. Fine for walls and low-traffic floors; check the PEI rating before using anywhere with regular foot traffic.
Standard: Standard porcelain tile at $3–$8 / sq ft. PEI 4 or 5 with rectified edges and convincing stone or wood looks. The mainstream choice for bathrooms, kitchens, and entries.
Premium: Premium porcelain or stone at $8–$25 / sq ft. Large-format porcelain or natural stone (marble, travertine, slate). The look that ages best and wears longest.
Don’t forget backer board and waterproofing
Tile needs a rigid substrate or it cracks. On floors over plywood, use cement backer board or an uncoupling membrane (Schluter Ditra). On wet shower walls, use cement backer board with a waterproofing layer or a waterproof board system. Plan for 5 to 10 percent of your material budget for these , they determine whether the install lasts decades or fails in two years.
Read the flooring guide →Frequently asked questions
Why do I need waste percentage?
Every tile install produces cut-offs at walls, corners, around toilets, sinks, and other obstacles. Waste percentage covers those cuts plus a small reserve for breakage during transport, installer mistakes, and future repairs. Without it, you will run short mid-install and may not be able to match the same dye lot later. Straight grid layouts typically waste 10 percent; diagonal and brick offset closer to 15 percent; herringbone 20 percent or more. Add another 5 percent for very large tile (24 inches or bigger) because cut waste grows with tile size.
What size tile is most popular?
12x24 inch porcelain has become the mainstream choice for floors in the last decade, beating out the older 12x12 standard. It looks more contemporary, makes rooms feel larger, and has fewer grout lines to maintain. For walls and backsplashes, 3x6 subway tile remains the most popular shape, especially in white. Larger formats like 24x24 are growing in popularity for open-plan floors but require very flat substrates and longer set times.
How do I calculate grout amount?
Grout quantity depends on three things: total square footage, tile size, and grout joint width. Larger tiles have fewer joints per square foot, so they need less grout. Wider joints need more grout per linear foot. A 25 lb bag of unsanded grout covers roughly 100 square feet of large tile with a thin 1/8 inch joint, but only about 50 to 60 square feet of mosaic tile with the same joint width. The calculator handles the size-and-joint math automatically; always round up and buy at least one extra bag for repairs and color matching.
What’s the difference between thinset types?
Unmodified thinset is plain portland cement, sand, and water-retaining agents; it is required under uncoupling membranes like Schluter Ditra. Modified thinset adds polymer additives for better bond strength and flexibility; use it on cement backer board or directly on concrete. For large-format tile (15 inches or larger), use a medium-bed or large-format mortar that does not slump under heavy tile. Wet area showers usually require modified thinset rated for submerged use. Check both your tile manufacturer’s and substrate manufacturer’s recommendations before buying.
Do I need backer board?
Yes, in most cases. Tile needs a rigid, dimensionally stable substrate or it will crack. On floors over plywood subfloor, use cement backer board or an uncoupling membrane like Schluter Ditra. On wet shower walls, use cement backer board with a waterproofing membrane or a waterproof board system like Wedi or Kerdi-Board. On dry interior walls (like a kitchen backsplash), you can tile directly to drywall if it’s clean and primed, but cement backer board is still safer for heavy tile or natural stone.