The backer and drywall areas behind the tile, by room.
Shower Tile Calculator
InteriorQuick answer: a standard 3×3 ft shower tiled 7 ft high needs 72 ft² of tile — 83 tiles of 12×12 in, or 9 boxes at 10 ft² per box — with the 15% waste allowance showers demand. This calculator counts the three walls and the floor separately, so niches and benches don't ambush your order.
Area assumes a three-wall alcove or corner shower (one back wall plus two side walls). For a two-wall or neo-angle layout, tile one side wall less — reduce the depth wall by entering only the walls you will actually tile in a note for your supplier, or subtract that wall's area from the result.
How it works — the formula
Wall area = (Width × Height) + 2 × (Depth × Height) · Floor area = Width × Depth Tile area = (Walls + Floor) × (1 + waste %) · Tiles = ⌈ Tile area ÷ (Tile L × Tile W ÷ 144) ⌉ Boxes = ⌈ Tile area ÷ Coverage per box ⌉Showers earn their 15% waste allowance honestly: nearly every wall ends in a cut, the floor slopes to the drain, and mosaic floor sheets get trimmed on all four sides. Add a bench (about 4–6 ft²) or a tiled niche (about 3 ft² plus trim) to the result if your design has them. Keep one spare box from the same dye lot — a cracked shower tile five years from now is unmatchable otherwise.
Worked examples
| Shower | Area incl. waste | Tiles | Boxes |
|---|---|---|---|
| 3 × 3 ft, 7 ft high, floor tiled, 12×12 in tile, 15% waste | 82.8 ft² | 83 | 9 |
| 4 × 3 ft, 8 ft high, floor tiled, 6×6 in tile, 10% waste | 101.2 ft² | 405 | 11 |
| 3 × 4 ft, 7 ft high, pan floor, 12×24 in tile, 15% waste | 88.6 ft² | 45 | 9 |
Check the first row: back wall 3 × 7 = 21 ft², two side walls 21 ft² each, walls total 63 ft², floor 9 ft² — 72 ft². With 15% waste: 82.8 ft². A 12×12 tile is exactly 1 ft², so 83 tiles; boxes at 10 ft²: 9.
Frequently asked questions
How much tile do I need for a standard shower?
A 3×3 ft shower at 7 ft high: 63 ft² of wall + 9 ft² of floor = 72 ft², or ≈83 ft² to buy with 15% waste.
Why 15% waste for a shower?
Cuts on nearly every course, a sloped floor, and corners eating partials on both walls. Large-format tile in a small shower can need 20%.
How much does a box of tile cover?
Commonly 10–15 ft² for wall tile — use the coverage printed on your box for an exact count.
Should shower floor tile differ from wall tile?
Yes, usually small mosaics (≈2 in) that follow the drain slope and grip better. Large tile on a sloped floor is a classic mistake.
Does this include a niche or bench?
No — add ≈3 ft² for a niche and 4–6 ft² for a bench, including trim.
Related tools
Not for the shower — for the driveway project after it.
Bags for a mortar bed or a small slab pour.
Sand for mortar mixes, in tons and bags.
See the full list on the Home & DIY Calculators page.
Estimates only. Layout pattern (stacked, brick, diagonal), grout joint width and large-format lippage all change real counts; confirm the final quantity with your tile setter before ordering, and keep a spare box from the same dye lot.