Tile Calculator
Calculate tiles needed for a room, waste factor by layout, grout estimate, and total cost.
Tiles needed
How to calculate tiles needed
The math is simple: divide the room area by the area of a single tile, then add a waste factor. The calculator does it automatically, but it helps to know the formula so you can sanity-check the result and adjust for unusual situations.
Formula: tiles needed = (room area ÷ tile area) × (1 + waste). Make sure both areas are in the same units. Tile sizes are usually given in inches, so convert: a 12×12 in tile is 144 in² = 1 ft². A 12×24 in tile is 288 in² = 2 ft². A 6×6 in tile is 36 in² = 0.25 ft². The calculator handles the unit conversion for you.
Worked example: a 10 × 12 ft bathroom = 120 ft². With 12×12 in tiles (1 ft² each), that is 120 tiles bare. Add 10% waste for a standard straight-lay installation: 120 × 1.10 = 132 tiles. If the box contains 10 tiles, you need 14 boxes (132 ÷ 10 = 13.2, round up). Same room with 12×24 in tiles (2 ft² each): 60 tiles bare, 66 with waste. With 6 tiles per box, that is 11 boxes.
Why waste factor matters
The waste factor covers everything that does not end up in a clean grid on your floor: edge cuts, around-toilet cuts, pipe penetrations, breakage during transport, breakage during cutting, mistakes, and pattern matching. Skipping the waste factor is the single most common reason homeowners run out of tile mid-install, and the consequences are bad:
- Dye lot mismatch. Tiles are produced in batches. Two boxes of "white" from different lots can be subtly different shades. Once the install is paused for a re-order, the new box may not match — and you will see it.
- Discontinued lines. Tile SKUs come and go. The product you bought three months ago might no longer be stocked when you need 4 more tiles.
- Time and labor. A second store trip mid-install, plus waiting for thinset to set on what is already laid, easily costs a half day.
Recommended waste factors by layout:
- Straight-lay (grid): 10%. Tiles aligned to walls, minimal cutting except at edges.
- Diagonal: 15%. Tiles rotated 45°. Every edge tile is a cut, often two cuts.
- Herringbone, chevron, basket weave: 20%+. Pattern repeats require careful matching, and edges and ends always need custom cuts.
- Pinwheel, Versailles, hexagon: 20–25%. Same reason — multiple sizes interlock and edge cuts proliferate.
Choosing tile size
Tile size has a much bigger visual impact than most homeowners expect. The general rule: larger tiles in larger rooms, smaller tiles in smaller rooms— but there are many exceptions, and modern design often breaks this rule deliberately.
- Small tiles (4×4, 6×6, mosaic): work in small rooms, on shower floors (more grout = more grip), and as decorative accents. More grout joints = more visual texture, but also more cleaning.
- Medium tiles (12×12, 12×24): the workhorse sizes. Easy to handle, widely available, predictable cost. Great for kitchens, bathrooms, and most floors.
- Large tiles (18×18, 24×24, 24×48): make small rooms look bigger by reducing visual clutter from grout lines. Need a flatter substrate (lippage shows worse on big tiles) and more careful installation.
- Plank-style (6×24, 6×36, 8×48): mimic wood floors. Often laid in a 1/3 or 1/4 offset (not 50% — long planks crown in the middle and create lippage).
- Subway (3×6, 4×8, 4×12): classic for kitchen backsplashes and shower walls. Often a stacked or 50%-offset bond pattern.
Diagonal and pattern layouts
Pattern layouts are visually striking but eat tile. Always order extra:
- Diagonal (45°): every perimeter tile is a triangular cut. Add 15% waste minimum, 18% if the room is small (more edge per square foot).
- Herringbone: two perpendicular orientations alternate. Edges and ends always need cuts at multiple angles. Add 20% waste.
- Chevron: like herringbone but tiles are pre-cut at angles, so cuts at the edges are even more demanding. Add 20–25%.
- Versailles / French pattern: four different sizes interlock in a repeating motif. Add 20% and buy from a vendor that sells the pattern as a coordinated set.
- Hexagon: every edge tile is at least one cut, often non-90°. Add 15–20%, more if the room is irregular.
For pattern layouts, plan the layout on graph paper or in a CAD app first. Starting in the wrong corner can leave you with a tiny sliver tile at a visible doorway — which looks bad and is hard to cut cleanly.
Don't forget grout, thinset, and underlayment
The tile is maybe 60–70% of the total cost. The rest is what makes the tile work:
- Thinset mortar: 1 bag (50 lb) covers ~50 ft² for medium tiles, less for larger tiles (which need a thicker bed). Modified thinset for most porcelain. Unmodified for natural stone over uncoupling membrane.
- Grout: 5–10% of the tile area, depending on joint width and tile size. Smaller tiles + wider joints = more grout. Sanded grout for joints over 1/8 in, unsanded for narrower joints, epoxy grout for showers and high-moisture areas.
- Underlayment / backer board: cement board (HardieBacker, Durock) for floors and walls. Uncoupling membrane (Schluter Ditra) for floors that may flex. Waterproofing membrane (Schluter Kerdi, RedGard) for showers and wet areas.
- Tile spacers: a few dollars, but essential for consistent grout joints. Match the size to your planned joint (1/16, 1/8, 3/16, 1/4 in).
- Sealer: for natural stone, unglazed porcelain, and grout (after curing). Penetrating sealer is the standard.
- Cutting tools: wet saw rental (~$50/day) for porcelain and stone. A snap cutter handles ceramic. A nipper handles small irregular cuts.
Common tile installation costs
Total installed cost varies wildly by region, tile, and complexity. Rough US ranges (2025):
- Tile material: ceramic $1–5/ft², porcelain $3–10/ft², natural stone $7–20/ft², handmade or designer $15–40+/ft².
- Labor (pro): $5–15/ft² for straight-lay floors, $10–25/ft² for walls, showers, or pattern layouts. Higher in HCOL metros.
- Materials beyond tile: $1–3/ft² for thinset, grout, backer board, sealer.
- Demo / removal of old floor: $2–5/ft² extra if there is existing tile or vinyl to remove.
- Total installed range: $8–25/ft² typical, $30+/ft² for high-end stone or pattern work.
DIY vs pro: a competent DIYer can save the labor portion (often half the total), but expect a slow first project. Plan for one weekend per ~50 ft², plus a day for grout and a day to seal. The tools (wet saw, trowels, mixing paddle, level, suction cups, knee pads) add ~$200 if you buy basic, less if you rent the wet saw.
For other home calculations, try the Paint Calculator for gallons and cost in any room, the Square Footage Calculator for areas of any shape, and the Concrete Calculator for slabs and footings.