Shower Tile Calculator: How Many Tiles You Need
Enter shower wall and floor dimensions plus tile size to get exact tile count, boxes needed, and waste allowance.
Shower Tile Calculator: How Many Tiles You Need
Calculator
Adjust values & calculateEnter your values below. Every result is computed in your browser — no data is sent to any server.
Formula: Tiles = Total Area / (Tile Width + Grout) x (Tile Height + Grout)
Additional inputs: Waste Factor (%), Tile Cost ($/sq ft) — optional.
Worked example — 765 tiles needed (3x6 subway) | 92 sq ft total | 77 boxes of 10
Formula
Tiles = Total Area / (Tile Width + Grout) x (Tile Height + Grout)
The calculator computes the total tiling area from shower dimensions (walls and optionally floor), then divides by the area of each tile including its grout joint. A waste factor is applied to account for cuts, breakage, and pattern matching.
Worked Examples
Example 1: Standard 3-Wall Shower with Subway Tiles
Problem:A shower is 5 ft wide, 3 ft deep, 7 ft tall with 3 tiled walls and floor. Using 3x6 inch subway tiles with 3mm grout and 10% waste.
Solution:Wall area: (60 x 84) + 2 x (36 x 84) = 5,040 + 6,048 = 11,088 sq in Floor area: 60 x 36 = 2,160 sq in Total: 13,248 sq in = 92 sq ft Tile + grout: 3.118 x 6.118 = 19.08 sq in/tile Tiles needed: 13,248 / 19.08 = 695 tiles With 10% waste: 695 x 1.10 = 765 tiles
Result:765 tiles needed (3x6 subway) | 92 sq ft total | 77 boxes of 10
Example 2: Large Format Wall Tiles
Problem:A 4 ft x 3 ft shower, 6.5 ft high, 3 walls only (no floor tile). Using 12x24 inch tiles, 3mm grout, 15% waste. Tile cost $8/sq ft.
Solution:Wall area: (48 x 78) + 2 x (36 x 78) = 3,744 + 5,616 = 9,360 sq in = 65 sq ft Tile + grout: 12.118 x 24.118 = 292.31 sq in/tile Tiles needed: 9,360 / 292.31 = 33 tiles With 15% waste: 33 x 1.15 = 38 tiles Cost: 65 x $8 x 1.15 = $598.00
Result:38 tiles needed (12x24) | 65 sq ft | Estimated cost: $598
Frequently Asked Questions
How do I measure my shower for tile?
To accurately measure your shower for tile, start with the three walls. Measure the width (back wall) and depth (side walls) in feet. Measure the height from the shower floor to where you want the tile to end, typically 72 to 96 inches. For each wall, multiply width by height to get the wall's square footage. If your shower has a window, door, or niche, measure those separately and subtract them from the total. For the floor, measure length times width. Always measure in the same units and convert to square feet by dividing square inches by 144. Add 10% to 15% waste factor for cuts, breakage, and pattern matching.
What size tile is best for a shower?
Tile size for showers depends on the area being tiled and the design aesthetic. For shower floors, smaller tiles (1x1 inch or 2x2 inch mosaics) are preferred because they conform better to the slope toward the drain and provide more grout lines for traction. For shower walls, popular sizes include 3x6 inch subway tiles for a classic look, 12x24 inch large format tiles for a modern feel, and 4x4 inch tiles for traditional designs. Larger tiles mean fewer grout lines and easier maintenance, but they require a very flat surface. Smaller tiles are more forgiving on uneven walls and curved surfaces but require more grout maintenance.
How much extra tile should I buy for waste?
The standard recommendation is to buy 10% to 15% extra tile for waste, but this varies based on several factors. A 10% overage is sufficient for straightforward rectangular layouts with standard-sized tiles. Increase to 15% for diagonal or herringbone patterns, which generate more cuts. For natural stone tiles that may have color variations or defects, consider 15% to 20% extra. If your shower has multiple niches, windows, or complex angles, add 15% to 20%. Always buy all your tile from the same lot number to ensure color consistency, and save a few extra tiles for future repairs. Running out of tile mid-project can be costly if the lot is discontinued.
What grout width should I use for shower tile?
Grout joint width depends on the tile size and type. For rectified (precisely cut) tiles, a 1/16 inch (1.5mm) joint gives a modern, minimal look. Standard grout joints are 1/8 inch (3mm) for most wall tiles, which is the most common choice for shower installations. Larger tiles (12 inches and above) typically use 1/8 to 3/16 inch joints. Natural stone tiles need wider joints of 3/16 to 1/4 inch to accommodate size variations. Mosaic sheets come pre-spaced at 1/8 inch. For shower applications, use epoxy grout or high-quality sanded grout with a sealer, as these resist moisture and mold better than unsanded grout, which is only suitable for joints under 1/8 inch.
Do I need to tile the shower ceiling?
Tiling the shower ceiling is not strictly required but offers several advantages, especially in steam showers where it is essential. A tiled ceiling provides superior waterproofing compared to painted surfaces, prevents peeling paint from moisture damage, makes cleaning easier, and gives the shower a polished, finished look. If you choose not to tile the ceiling, use moisture-resistant paint or PVC panels rated for high-humidity environments. For standard showers, moisture-resistant drywall with quality paint is acceptable, but for steam showers or showers used by multiple people daily, tile is the best long-term investment to prevent moisture damage to the structure above.
What is the difference between a sheet membrane and a liquid-applied waterproofing system?
Both create the continuous waterproof plane that tile and grout cannot provide on their own, since grout is porous and water reaches the substrate behind it. A bonded sheet membrane is a fabric-faced polyethylene rolled into thinset over the backer board, with seams and corners overlapped and banded; it has a known, uniform thickness the moment it is down. A liquid-applied membrane is rolled or trowelled on in multiple coats with reinforcing fabric at corners, which suits complex shapes but depends on hitting the manufacturer's wet-film thickness across every square foot. Whichever you use, it must tie into the drain flange to work.
Why does a shower floor need slope, and how much?
The floor must move water to the drain rather than let it pond against the tile and grout, and the standard practice used across tile industry guidance is about one quarter inch of fall per foot of run from the perimeter to the drain. In a traditional mortar-bed shower that slope has to exist twice: a pre-slope under the pan liner so water reaching the liner drains out through the weep holes, and the finished slope in the mortar above it. Omitting the pre-slope leaves water trapped in a flat bed under the tile, which is a common source of odour and mildew in otherwise sound showers.
How do I plan tile layout around a shower niche and curb?
A niche is not just a hole in the wall; its back, sides, top, and bottom all get tiled, so add that surface to the wall total Shower Tile Calculator: How Many Tiles You Need produces, and slope the niche shelf slightly forward so water sheds. Position the niche so its opening lands on full-tile grout lines rather than forcing thin slivers at the edges, which usually means setting the niche height and width from the tile module rather than the other way round. A curb is tiled on three faces, top, inside, and outside, and the top should pitch slightly back into the shower.
What mortar coverage does large-format tile require behind it?
Voids behind tile are where cracks and hollow spots begin, and large tiles bridge trowel ridges rather than collapsing them. The fix is to comb thinset in one direction with a suitably deep notched trowel, back-butter a thin skim across the back of each tile, then set it by sliding perpendicular to the ridges so they flatten rather than trap air. Industry guidance for wet areas calls for essentially full support of the tile back, so pull a set tile off early in the job and inspect the coverage before continuing. A large-format mortar rated for non-sag vertical use also stops big tiles from creeping downward.
Where should silicone be used instead of grout in a shower?
Every change of plane needs a flexible sealant rather than rigid grout: the inside corners where two walls meet, the joint where walls meet the shower floor or curb, and the perimeter where tile abuts a tub or bench. Those joints move as framing shrinks and as the assembly warms and cools, and cement grout has no elasticity, so it cracks and lets water into the joint. Use a mildew-resistant silicone colour-matched to your grout, applied after the grout has cured, and rake out any grout already packed into those corners first.
References
Reviewed for accuracy by Daniel Agrici, Founder & Lead Developer · Editorial policy
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