Calculator — Kitchen & Bath
Shower Tile Calculator
Tiles and boxes for a shower — wall area from perimeter times height minus openings, floor counted separately, with waste allowance.
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About this calculator
A shower is two tile jobs: walls measured by perimeter times height, and the floor measured like any room. This calculator counts both, deducts windows, niches and glass panels, and converts the total into tiles and whole boxes at your waste allowance.
What this number means
A shower is two tile jobs in one: the walls, measured by perimeter times height, and the floor, measured like any room. The walls dominate — a modest 5 × 3 ft shower tiled to 8 ft has 128 sq ft of wall against just 15 sq ft of floor — which is why a shower tile count surprises people who only measured the footprint.
The waste allowance matters more here than on a floor because every wall ends in cuts: corners, the showerhead wall, the curb and any niche. Ten percent covers a straight lay; go to 15% for a diagonal pattern or a shower with a lot of niches and fixtures. And buy the boxes, not just the tiles — tile dye lots vary, so a spare box from the same lot is worth more than a perfect count.
The formula
- Perimeter = 2 × (Length + Width) (ft)
- Wall area = Perimeter × Wall height − Openings (sq ft)
- Floor area = Length × Width (sq ft)
- Total area = Wall area + Floor area
- Tiles = Total area × (1 + waste %) ÷ tile area, rounded up
- Boxes = Tiles ÷ tiles per box, rounded up
Worked example
A 5 × 3 ft shower tiled to 8 ft high, 12 × 12 in tiles, no openings, 10% waste, 10 tiles per box.
- Perimeter: 2 × (5 + 3) = 16 ft
- Wall area: 16 × 8 = 128 sq ft
- Floor area: 5 × 3 = 15 sq ft
- Total: 128 + 15 = 143 sq ft → with 10% waste: 157.3 sq ft
- Tiles: 157.3 ÷ 1 sq ft per tile = 158 tiles → 16 boxes
Assumptions and limitations
- Wall area assumes all four sides are tiled to the stated height. If one side is a glass panel, deduct its area in the openings field — a 3 ft wide panel to 8 ft high is 24 sq ft, which would cut the worked example to 131 tiles.
- Grout joints are not deducted: tile counts use the nominal tile area, which slightly overstates coverage and acts as a small safety margin.
- The floor is counted with the same tile size as the walls. If the floor uses a different format (common — smaller tiles grip better wet), run the floor separately with the Tile Calculator.
- Thinset, grout, waterproofing membrane and trim are not included — tile count is not a full shower materials list.
- Keep at least one spare box from the same dye lot for future repairs; tile shades vary between lots.
Frequently asked questions
A typical 5 × 3 ft shower tiled to 8 ft high needs about 158 × 12 × 12 in tiles at 10% waste (143 sq ft of surface). Smaller tiles raise the count fast: the same shower in 3 × 6 in subway tile needs 1,259 tiles.
It can, but many installers use a smaller format on the floor — 2 × 2 in mosaics are standard — because more grout joints mean better grip when wet. If the floor format differs, count it separately with the Tile Calculator and add it to the wall count here.
Use 10% for a straight lay on plain walls. Use 15% for a diagonal or herringbone pattern, or for a shower with niches, benches, windows and many fixture cutouts — every one of those is a cut tile.
Yes — any area that will not be tiled goes in the openings field. A 3 ft wide glass panel tiled to 8 ft high deducts 24 sq ft; on the worked example that drops the count from 158 to 131 tiles.
No. It counts tiles and boxes only. For grout quantities by tile size and joint width, use the Grout Calculator; thinset coverage (typically 40–50 sq ft per 50 lb bag for large-format tile) comes from the product label.
Tile dye lots vary in shade, and a future repair with a different lot will show. Buy one spare box from the same lot as the install — it costs little now and may be impossible to match later.