Calculate exactly how many tiles, boxes, and grout you need for any flooring or wall project. Enter your room dimensions, choose your tile size, and we'll factor in waste and grout spacing for a professional estimate.
Room Dimensions
Tile Specifications
Standard: 10% for straight lay, 15% for diagonal, 20% for herringbone.
Cost Settings
Typical: 10–15 tiles/box. Check your specific tile packaging.
Ceramic $25–$50/box. Porcelain $40–$80/box.
Avg pro install: $5–$12/sqft. More for intricate patterns or large-format.
🔲 Tile Estimate
Total Area—
Tile Size—
Area per Tile—
Tiles Needed (exact)—
Waste Factor—
Tiles Including Waste—
Boxes Needed (rounded up)—
Grout Needed—
Total Tile Cost—
Installation Cost (pro install)—
Grout Cost—
Project Total (materials + install)—
Tip: Always buy at least one extra box. If you crack a tile during a future repair, having matching dye-lot tiles on hand is invaluable.
How to Use the Tile Calculator
Measure the length and width of your room in feet. Multiply them to get your total square footage — that's your coverage area. Choose your tile size from the dropdown, or select "Custom Size" for any non-standard tile dimensions.
The waste factor accounts for cuts, breakage, and pattern matching. For a standard straight-lay (grid) pattern, 10% is sufficient. Diagonal layouts need 15%, and complex patterns like herringbone can require up to 20% extra. Always round up when buying boxes — running short means delays and potential dye-lot mismatches.
Grout is calculated based on total linear feet of grout lines (derived from tile size, spacing, and total area). The formula uses the industry-standard coverage rate for sanded grout: approximately 0.5–1.5 lbs per square foot depending on tile size and joint width. Larger tiles and tighter joints use less grout; smaller tiles with wider joints use more.
Tile Installation Tips
Dry-lay first. Before mixing any mortar, lay out tiles to visualize the pattern, check for dye-lot consistency, and plan cuts at edges. Adjust starting position so you don't end up with a sliver-thin cut at the wall.
Use the right trowel. Larger tiles need deeper notches. 12×12 tiles use a 1/4″×3/8″ square-notch trowel; large-format tiles (12×24+) need a 1/2″×1/2″ trowel or larger for proper mortar coverage.
Back-butter large tiles. For any tile over 12″ in any dimension, apply a thin skim coat of mortar to the back of the tile before setting it. This ensures full coverage and prevents hollow spots.
Use leveling clips for large-format tile. Tiles 12×24 and larger are rarely perfectly flat. A lippage control system (leveling clips and wedges) prevents uneven edges that catch toes and cast shadows.
Seal grout after 72 hours. Wait at least 3 days for grout to fully cure, then apply a penetrating sealer. Re-seal every 1–2 years in high-moisture areas like showers.
A 12×12 tile covers exactly 1 square foot, so a 100 sq ft room needs 100 tiles exactly. With a 10% waste factor, you'd need 110 tiles. If each box contains 12 tiles, that's 10 boxes (9.17 rounded up). Total tile cost at $45/box: $450. Always order at least one extra box to account for cuts, breakage, and future repairs.
Use sanded grout for joints 1/8″ and wider — the sand adds strength and prevents shrinkage cracking. Use unsanded grout for joints narrower than 1/8″ and for polished/scratch-prone tiles like marble or glass. Epoxy grout is an upgrade option: it's stain-proof, waterproof, and never needs sealing, but it's harder to work with and costs 3–5× more than cement-based grout.
Standard waste factor is 10% for straight-lay patterns in rectangular rooms. Increase to 15% for diagonal layouts and 20% for herringbone or Versailles patterns. Rooms with lots of angles, curves, or obstacles (toilets, cabinets) also need 15%+. Always round up to full boxes — you can't return opened boxes at most stores, but unopened ones can usually be returned.
Yes, you can tile over existing tile if: (1) the existing tile is firmly bonded with no hollow spots, (2) the floor can handle the additional height and weight, and (3) you mechanically abrade the old tile surface and use a high-quality modified thinset rated for tile-over-tile. However, removing old tile gives a better, longer-lasting result. Tile-over-tile also raises your floor height, which may require trimming doors and adjusting transitions.
Ceramic tile runs $2–$8/sqft for materials, while porcelain runs $4–$15/sqft. Porcelain is denser, more water-resistant, and more durable — it's the better choice for bathrooms, kitchens, and high-traffic areas. Ceramic is easier to cut and works well for walls and low-traffic floors. Installation costs are similar ($5–$12/sqft), though porcelain's hardness may add a small upcharge for cutting. For outdoor use, only through-body porcelain is freeze-thaw rated.