How Much Tile to Buy: Quantity Calculator for Any Room and Tile Size
For a standard 10×12 bathroom floor (120 sq ft) using 12×12 tiles laid straight, order approximately 138 square feet of tile (120 sq ft plus 15% waste). One box of 12×12 tiles typically covers 10 to 15 sq ft. How much tile to buy depends on tile size (larger tiles waste more at cuts), installation pattern (diagonal wastes 15-20%, straight wastes 10%), and grout joint width. Always round up to the nearest full box and buy all tile from the same production lot.
Tile is the most unforgiving flooring material to under-order. Unlike laminate or LVP where you might find matching material within a week, specific tile products can be discontinued, or the same tile from a different production lot can have visible shade variation that makes it obvious where you ran short and added more. The 15-minute time investment in an accurate tile quantity calculation before purchase is one of the best ROI decisions in any tile project.
The tile calculator converts room dimensions to tile boxes with waste factor, grout, and thinset quantities.
Open the Tile Calculator →Waste Factor by Tile Size and Installation Pattern
| Tile size | Straight lay waste | Diagonal lay waste | Herringbone waste |
|---|---|---|---|
| 4×4 (small mosaic) | 5 to 8% | 10 to 12% | 12 to 15% |
| 6×6 | 8 to 10% | 12 to 15% | 15 to 18% |
| 12×12 (standard) | 10 to 12% | 15 to 18% | 18 to 22% |
| 12×24 (rectangular) | 12 to 15% | 18 to 22% | 20 to 25% |
| 18×18 | 12 to 15% | 18 to 22% | 20 to 25% |
| 24×24 (large format) | 15 to 18% | 20 to 25% | 22 to 28% |
| Subway (3×6 or 4×8) | 10 to 12% | 15 to 18% | 15 to 20% |
Tile Boxes Needed by Room Size and Tile Format
| Room area | Area with 15% waste | Boxes (10 sq ft/box) | Boxes (12 sq ft/box) |
|---|---|---|---|
| 60 sq ft (small bath) | 69 sq ft | 7 boxes | 6 boxes |
| 80 sq ft (bathroom) | 92 sq ft | 10 boxes | 8 boxes |
| 120 sq ft (full bath) | 138 sq ft | 14 boxes | 12 boxes |
| 200 sq ft (kitchen) | 230 sq ft | 23 boxes | 20 boxes |
| 300 sq ft (entryway+hall) | 345 sq ft | 35 boxes | 29 boxes |
| 500 sq ft (open floor plan) | 575 sq ft | 58 boxes | 48 boxes |
Tile box coverage varies significantly by product: always use the square feet per box printed on the product label, not a general estimate. For mosaic sheets on a mesh backing, the coverage is listed for the mesh sheet area, not the individual tile pieces. For the flooring material comparison that might replace tile in some rooms, our laminate vs LVP vs hardwood guide covers the alternatives. For the pattern cost difference between herringbone and straight installation, our herringbone vs straight tile guide covers the labor and material premium for decorative patterns. For a related flooring waste factor comparison, our flooring waste factor guide covers the same calculation for LVP and hardwood.
Grout and Thinset Quantity
| Tile size | Joint width | Grout (lbs per 100 sq ft) | Thinset (50-lb bags per 100 sq ft) |
|---|---|---|---|
| 4×4 | 3/16 inch | 20 to 25 lbs | 1 bag |
| 6×6 | 3/16 inch | 12 to 16 lbs | 1 bag |
| 12×12 | 1/8 inch | 8 to 12 lbs | 1 bag |
| 12×24 | 1/8 inch | 6 to 9 lbs | 1 bag |
| 18×18 | 3/16 inch | 8 to 11 lbs | 1 bag |
| 24×24 | 1/4 inch | 8 to 11 lbs | 1 to 1.5 bags |
| Subway 3×6 | 1/8 inch | 15 to 20 lbs | 1 bag |
One 25-lb bag of sanded grout covers approximately 40 to 80 sq ft depending on tile size and joint width. One 50-lb bag of thinset mortar covers approximately 80 to 120 sq ft at standard trowel depth (3/8 inch square notch trowel for 12×12 tiles). Large format tiles (18×18 and larger) require back-buttering each tile in addition to the trowel application, which doubles thinset consumption: use 2 bags per 100 sq ft for tiles 18 inches or larger.
Shade Variation and Dye Lot
Natural stone tiles and some porcelain products have inherent shade variation from piece to piece. Manufacturers grade tile by shade consistency: Grade 1 (uniform shade), Grade 2 (moderate variation), Grade 3 (significant variation). For Grade 2 and 3 products, a professional installer dry-lays tiles from multiple boxes, mixes them, and installs from the mix to distribute the natural variation evenly across the floor. This technique requires having all material on-site before starting and is why ordering all tile in one purchase from the same production lot is essential for shade-variable products.
Three Real Tile Projects
Example 1: Master bathroom floor in Nashville, Tennessee
A homeowner tiling a 9×11 master bathroom floor (99 sq ft) with 12×24 porcelain in a staggered brick pattern. Tile size 12×24 in brick pattern: 15% waste. 99 x 1.15 = 113.85 sq ft. Product: 12×24 tile in boxes of 15.5 sq ft (4 tiles per box). Boxes: 113.85 / 15.5 = 7.3 boxes. Ordered 8 boxes (124 sq ft). Grout (unsanded, 1/16-inch joints): 7 lbs per 100 sq ft x 124 = 8.7 lbs, purchased 10-lb bag. Thinset for 12×24 with back-buttering: 2 bags of 50 lbs. Total materials: 8 boxes tile ($312) + grout ($14) + thinset ($42) = $368.
Example 2: Kitchen backsplash in Austin, Texas
A homeowner tiling a kitchen backsplash of 42 sq ft (all wall area between countertop and upper cabinets) with 3×6 subway tile in straight-lay pattern. Subway tile with 10% waste: 42 x 1.10 = 46.2 sq ft. Subway tile in boxes of 8.5 sq ft: 46.2 / 8.5 = 5.4 boxes. Ordered 6 boxes (51 sq ft). Unsanded white grout for subway tile (1/16-inch joints): 8 lbs for 51 sq ft. Mosaix-style thinset: 1 bag for walls. Total materials: 6 boxes ($144) + grout ($12) + thinset ($21) + tile spacers ($6) = $183.
Example 3: Large-format entryway tile in Phoenix, Arizona
A homeowner tiling a 12×18 entryway (216 sq ft) with 24×24 porcelain in straight-lay pattern. Large format 24×24 with 15% waste: 216 x 1.15 = 248.4 sq ft. Product in boxes of 16 sq ft (3 tiles per box): 248.4 / 16 = 15.5 boxes. Ordered 16 boxes (256 sq ft). Thinset for 24×24 with back-buttering: 2 bags per 100 sq ft x 256 = 5.1 bags, ordered 6 bags. Sanded grout (1/4-inch joints): 10 lbs per 100 sq ft x 256 = 25.6 lbs, ordered 2 x 15-lb bags. Total materials: 16 boxes tile ($1,120) + grout ($38) + thinset ($126) + lippage clips ($45) = $1,329. Lippage clips are essential for large-format tile to maintain consistent plane and prevent edge lippage visible in raking light.
The tile calculator handles any tile size and pattern. Enter dimensions and get boxes, grout, and thinset quantities.
Calculate Tile Boxes →Frequently Asked Questions About Tile Quantity
How much tile do I need for a 10×10 room?
A 10×10 room has 100 square feet. With 10 percent waste for a straight-lay installation using 12×12 tiles, order 110 square feet. If your tile comes in boxes of 10 sq ft, order 11 boxes. For a diagonal layout, use 15 percent waste (115 sq ft, 12 boxes). Always confirm the exact square footage per box on your specific product before dividing.
How do I calculate tile for a bathroom floor?
Measure the bathroom floor length x width in feet. Multiply by your waste factor (10% for straight lay, 15% for diagonal or large-format tiles). Divide by the square feet per box listed on the tile product. Round up to the next whole box. For a typical 8×10 bathroom (80 sq ft) with 12×12 tile at 15% waste: 80 x 1.15 = 92 sq ft. If the box covers 10 sq ft: buy 10 boxes.
What is the standard tile waste factor?
The industry standard waste factors are: 10 percent for small tiles (4×4, 6×6) in straight lay; 10 to 12 percent for 12×12 tiles in straight lay; 15 percent for any tile in diagonal lay; 15 to 20 percent for herringbone or chevron patterns; and 15 to 18 percent for large format tiles (18×18 and larger) due to the greater area wasted per cut piece.
How much grout do I need per square foot of tile?
Grout quantity depends on tile size and joint width. For 12×12 tiles with 1/8-inch joints: approximately 8 to 12 lbs per 100 sq ft. For small tiles (4×4) with 3/16-inch joints: 20 to 25 lbs per 100 sq ft. More grout joints (smaller tiles) and wider joints both increase grout consumption. Check the coverage chart on the grout bag label for your specific tile size and joint width combination.
How much thinset mortar do I need?
One 50-pound bag of thinset covers approximately 80 to 120 sq ft at standard trowel depth for 12×12 tiles. Large format tiles (18 inches and larger) require back-buttering each tile in addition to the floor application, which doubles consumption: plan for 2 bags per 100 sq ft for large-format tile. Always buy one bag more than calculated as a buffer for thick spots, substrate dips, and re-troweling mixed thinset that starts to set before use.
Should I use sanded or unsanded grout?
Unsanded grout for joints 1/8 inch wide or narrower (most wall tile, small-format floor tile with tight joints). Sanded grout for joints wider than 1/8 inch (most floor tile, larger format tile, any joint over 3/16 inch wide). Using unsanded grout in wide joints causes shrinkage cracking as the grout dries. Using sanded grout in very narrow joints scratches polished tile surfaces because the sand particles are too large to distribute in a tight joint.
What is tile shade variation and how do I handle it?
Shade variation refers to the natural color and tone differences between individual tiles in the same production lot, intentionally introduced by the manufacturer to mimic natural stone variation. Tiles are classified by shade variation level: V1 (uniform), V2 (slight), V3 (moderate), V4 (substantial). For V3 and V4 tiles, mix planks or tiles from at least three different boxes before installation to distribute the variation evenly across the floor. Dry-lay several rows before committing to the pattern to confirm the mix looks natural and no two very similar pieces end up adjacent.
Can I return unused tile boxes?
Most tile retailers accept returns of unopened, undamaged boxes within 30 to 90 days with receipt. Tile is heavy (a box of 12×12 tiles typically weighs 40 to 60 pounds) and must be returned undamaged. This is why buying one extra box rather than the exact calculated amount is standard: the extra box cost is worth having matching material for future repairs, and if not needed, it can be returned. Never dispose of leftover tile from the original lot; it is the only guaranteed source of matching material for future repairs.
Related Calculators and Guides
For tile installation standards, the Tile Council of North America (TCNA) Handbook is the definitive US reference for tile installation methods, substrate requirements, grout joint specifications, and thinset mortar selection for all residential and commercial tile applications.