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Kalcufy

Tile Calculator

Calculate how many tiles you need plus grout, thinset, and cost estimates for any floor, wall, or backsplash project.

Reference table

LengthTiles NeededTiles with WasteBoxes to Buy
0.55 tiles6 tiles (10% waste)1 box
110 tiles11 tiles (10% waste)2 boxes
1.515 tiles17 tiles (10% waste)2 boxes
220 tiles22 tiles (10% waste)3 boxes
2.525 tiles28 tiles (10% waste)3 boxes
330 tiles33 tiles (10% waste)4 boxes
440 tiles44 tiles (10% waste)5 boxes
550 tiles55 tiles (10% waste)6 boxes
660 tiles66 tiles (10% waste)7 boxes
770 tiles77 tiles (10% waste)8 boxes
880 tiles88 tiles (10% waste)9 boxes
990 tiles99 tiles (10% waste)10 boxes
10100 tiles110 tiles (10% waste)11 boxes
12120 tiles132 tiles (10% waste)14 boxes
15150 tiles165 tiles (10% waste)17 boxes

Pro Tips

  • Always buy tiles from the same batch/lot number. Color and shade vary between production runs, making later matching nearly impossible.
  • Keep 2-3 extra tiles for future repairs. Store them flat in a dry area. Replacement tiles from a different batch will look noticeably different.
  • Start tiling from the center of the room, not from a corner. This ensures balanced cuts at all walls and avoids tiny slivers along one edge.
  • Use the correct trowel size: 1/4" notch for small tiles, 3/8" for 12" tiles, and 1/2" for large format tiles (18"+).

What Is a Tile Calculator?

A tile calculator helps you estimate the exact number of tiles, grout, and thinset mortar needed for your flooring, wall, or backsplash project. Rather than guessing and risking running short (or over-buying), a proper tile calculation considers the area to cover, tile dimensions, grout joint width, layout pattern, and a waste factor for cuts and breakage. This calculator goes beyond simple tile counting by also estimating grout volume based on joint dimensions, thinset coverage based on tile size and trowel selection, and total project cost when material prices are provided. Whether you're tiling a small bathroom floor or a large living room, accurate material estimates save money, prevent project delays, and ensure consistent results from the same tile batch.

How Tile Estimation Works

The calculation begins by determining the total area to tile (length × width). Next, it calculates the coverage area of each individual tile by converting tile dimensions from inches to square feet. The base tile count is the total area divided by the area per tile, rounded up. A waste factor is then applied based on your chosen layout pattern: straight grid patterns produce the least waste (10%), while herringbone and complex patterns generate more offcuts that can't be reused (15-20%). For grout, the calculator determines the total linear footage of grout joints using tile size and spacing, then computes the volume based on joint width and tile thickness (which determines joint depth). Thinset mortar is simpler — it covers the entire area as a continuous bed, so the calculation divides total area by the bag's coverage rate. Different trowel sizes affect coverage: a 1/4" notch trowel spreads thinner, covering more area per bag, while a 1/2" notch for large tiles uses more material per square foot.

Important Considerations

  • Grout joint width affects both appearance and material needs. Narrow joints (1/16") create a sleek modern look but require rectified tiles. Standard joints (1/8") work for most installations.
  • Use sanded grout for joints 1/8" or wider — the sand particles provide structural strength. Use unsanded grout for joints under 1/8" — sand can scratch delicate glass or polished stone tiles.
  • Large format tiles (18"+ on any side) require a 1/2" notch trowel, latex-modified thinset, and back-buttering for proper adhesion. Coverage per bag drops significantly.
  • Diagonal, herringbone, and chevron patterns require 15-20% more tile than grid layouts. The angled cuts create triangular waste pieces that usually cannot be reused elsewhere in the layout.
  • Natural stone tiles (marble, granite, travertine) need sealing before grouting to prevent stain absorption. They also require white thinset — gray thinset can show through translucent stones.
  • For wet areas (showers, pool surrounds), epoxy grout provides superior water resistance and chemical durability. It costs more but prevents mold growth and staining in high-moisture environments.

Tile Layout Patterns

  • Grid (Straight Set): The most common and efficient pattern. Tiles align in rows and columns with joints forming a straight grid. Waste is minimal at 10%. Works with any tile size.
  • Diagonal (45°): Same grid rotated 45 degrees. Creates a diamond effect that makes small rooms appear larger. Requires 15% extra tile for angled edge cuts.
  • Running Bond (Brick Pattern): Each row is offset by half a tile width, like brickwork. Adds visual movement and hides slight size variations. Requires 12% extra tile.
  • Herringbone: Rectangular tiles arranged in a V-shaped zigzag. Creates a dramatic, high-end look especially in entryways and corridors. Requires 20% extra for many angled cuts.
  • Subway Pattern: Typically 3×6" tiles in running bond. The most popular backsplash pattern. Can be laid horizontally (classic) or vertically (modern). Standard 12% waste.
  • Versailles / French Pattern: Uses 3-4 different tile sizes in a repeating pattern. Complex to plan but creates an elegant, European look. Waste varies by specific pattern (15-20%).

Tile Calculation Examples

Step-by-step examples for common projects

Bathroom Floor: 8×10 ft with 12×12" tiles, grid layout

  1. Total area = 8 × 10 = 80 sq ft
  2. Tile area = (12 × 12) ÷ 144 = 1.0 sq ft per tile
  3. Base tiles = 80 ÷ 1.0 = 80 tiles
  4. Waste (grid, 10%) = 80 × 0.10 = 8 tiles
  5. Total tiles = 80 + 8 = 88 tiles
  6. Grout (1/8" joint, 3/8" thick): ~7 lbs → 1 bag (25 lb)
  7. Thinset (80 sqft/bag): 80 ÷ 80 = 1 bag

Buy 88 tiles (9 boxes of 10). 1 bag grout, 1 bag thinset.

Entry: 6×8 ft with 3×6" subway, herringbone layout

  1. Total area = 6 × 8 = 48 sq ft
  2. Tile area = (3 × 6) ÷ 144 = 0.125 sq ft per tile
  3. Base tiles = 48 ÷ 0.125 = 384 tiles
  4. Waste (herringbone, 20%) = 384 × 0.20 = 77 tiles
  5. Total tiles = 384 + 77 = 461 tiles
  6. Grout (1/8" joint): ~12 lbs → 1 bag (25 lb)
  7. Thinset (95 sqft/bag): 48 ÷ 95 ≈ 1 bag

Buy 461 tiles (6 boxes of 80). 1 bag grout, 1 bag thinset.

Frequently Asked Questions

How many extra tiles should I buy for waste?

It depends on your layout pattern and room complexity. For a simple grid layout in a rectangular room, 10% extra is standard. Diagonal patterns need 15% extra, and herringbone or chevron patterns need 20% extra due to the many angled cuts. If your room has alcoves, columns, or irregular shapes, add an additional 5%. Always buy all tiles from the same production batch, as color and shade vary between runs. Keep a few spare tiles stored for future repairs.

What's the difference between sanded and unsanded grout?

Sanded grout contains fine sand particles that provide structural strength and prevent shrinkage in wider joints. Use it for grout joints 1/8" or wider — it's the standard for floor tiles and most wall applications. Unsanded grout has a smoother texture and is used for joints narrower than 1/8", typically with glass tiles, polished marble, or small mosaics where sand particles could scratch the tile surface. Epoxy grout is a third option that provides superior water and chemical resistance for wet areas like showers and pools, though it's more expensive and harder to work with.

How do I choose the right trowel size for thinset?

Trowel size depends on your tile size. For small tiles under 8×8 inches, use a 1/4" × 1/4" square-notch trowel (covers ~95 sq ft per bag). For medium tiles around 12×12 inches, use a 3/8" × 3/8" square-notch trowel (~80 sq ft per bag). For large format tiles 18 inches or larger, use a 1/2" × 1/2" square-notch trowel (~60 sq ft per bag). Always check the thinset bag label for specific coverage rates, as they vary by product and manufacturer.

Can I use this calculator for wall tiles?

Yes. Select "Wall" or "Backsplash" as the surface type. For walls, enter the wall length and the height you want to tile. The tile count, grout, and thinset calculations work the same way for walls and floors. The main difference is that walls typically use mastic adhesive (for small ceramic tiles) instead of thinset, though large format wall tiles still require latex-modified thinset for proper weight support.

Does grout joint width affect how many tiles I need?

Technically yes, but the effect is small and usually covered by your waste percentage. Wider grout joints (1/4" or 3/8") reduce the number of tiles slightly because the joints take up more space. For example, in a 100 sq ft room with 12×12" tiles, 1/4" joints save about 2-3 tiles compared to 1/16" joints. The more significant impact of grout width is on grout quantity — wider joints require substantially more grout material.

How accurate is this calculator compared to professional estimates?

This calculator provides estimates within 5-10% of professional tile installer quotes for standard rectangular spaces. It uses industry-standard formulas for tile count, grout volume, and thinset coverage. For complex spaces with many cuts, angled walls, or multiple alcoves, a professional site visit will give a more precise estimate. Always round up when purchasing — having a few extra tiles is far better than running short mid-project and discovering your tile has been discontinued or the new batch doesn't match.

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