Tile Calculator

How to measure for tile

1. Floor: area = length x width. Walls: sum each wall area you'll tile.
2. Subtract large openings only if you need a tighter estimate.
3. Increase waste for diagonal layouts, patterns, and small-format tiles.
4. If you’re mixing sizes (field tile + mosaics), estimate each area separately and then combine the totals.
5. For showers, include all planes you will tile (walls, niche back/sides, bench faces, curb) and sum their areas.
6. If the tile pattern has a specific module (mosaic sheets, patterns, or border layouts), measure that area separately and plan extra waste for pattern alignment.
7. Convert to boxes using the product’s stated coverage per box, then round up to whole boxes.
8. Count edges that need trims/bullnose and estimate those pieces separately from field tile boxes.
9. If it is a wet area, estimate waterproofing/membrane coverage as a separate materials line item (and include overlaps, bands, and corners per the system).

Assumptions to double-check

• Coverage per box varies by tile size and packaging—use label coverage.
• Patterns and many cuts can push waste beyond 10-15%.
• A 10% overage is a starting point, not a rule—raise it for complex layouts or many penetrations.
• Mosaics and feature borders often require separate estimating.
• Some tile types (natural stone, large-format) can have higher breakage risk—plan extra for handling and cuts.
• You’re estimating finished tiled surfaces, not the room footprint that includes cabinets, tubs, or other untiled zones.
• Layout changes (pattern, grout joint width, trim decisions) can change waste even if total area is unchanged.
• Wet areas usually require a waterproofing membrane system and compatible mortars (project dependent). Material compatibility and install steps matter as much as quantity.
• If the substrate is not flat enough for your tile size, you may need additional prep materials; trying to fix flatness with thinset can increase waste and failure risk.
• Grout joint width and trim profile choices can change the effective layout and where cuts land, even if area is unchanged.

Buying tips

• Buy extra from the same lot/dye batch for color consistency.
• Round up your waste factor for complex layouts or many corners.
• Keep a few spare tiles after installation for future repairs.
• If availability is uncertain, buying one extra box can prevent future mismatches.
• Open and inspect a few boxes before installing; mix boxes to blend shade variation if needed.
• Confirm waterproofing and thinset compatibility for wet areas (system approach reduces failures).
• Choose the right cutting tool for the tile type and thickness; reducing breakage can be worth the rental cost.
• For showers, price the full system: backer/substrate, membrane, banding/corners, drain integration, mortar, and grout. Tile boxes are only part of the cost.
• If you're using large-format tile, confirm trowel size and coverage guidance; poor coverage can cause hollow spots and cracked tile (project dependent).
• If your system requires a flood test (common for showers), schedule time for it before tile goes up. A failed test is cheaper to fix before you set tile.

Common mistakes to avoid

• Using a low waste factor on complex layouts (diagonal, herringbone, many corners).
• Forgetting to estimate mosaics/borders separately when they have different box coverage.
• Not keeping spare tiles for future repairs (same lot if possible).
• Assuming every box has the same coverage—packaging varies by product and thickness.
• Forgetting extra tiled surfaces (niches, benches, curbs) and then running short on matching tile.
• Not verifying dye-lot consistency before installing, then discovering mismatches too late.
• Skipping waterproofing details in wet areas and assuming grout/caulk will keep water out.
• Starting layout without checking for out-of-square walls, then ending up with sliver cuts and extra waste at the finish.