Shower Tile Calculator
Calculate tiles needed for shower walls and floor separately, including waste for cuts around the drain, niche, and fixtures.
How to Use This Calculator
Calculate shower walls and the shower floor separately — they typically use different tile sizes, which means different waste percentages and tile counts. For each wall, enter the wall width and height in the length and width fields. Run the calculator for each wall and add the tile counts. Subtract any large openings (windows, niches over 6 sq ft). For the shower floor, enter the floor length and width, choose your small-format tile size, and use at least 15% waste. Enter tiles per box from the product label to get your box total.
How to Calculate Shower Tile
Shower wall area: add up each wall's height × width. For a standard 3-wall shower enclosure 3 ft × 4 ft × 8 ft tall: back wall = 3 × 8 = 24 sq ft, two side walls = 2 × (4 × 8) = 64 sq ft. Total wall area = 88 sq ft. With 15% waste: 88 × 1.15 = 101.2 sq ft of wall tile.
Shower floor area: 3 × 4 = 12 sq ft. With 20% waste for mosaic tile cuts around the drain: 12 × 1.20 = 14.4 sq ft. For 2×2 mosaic tiles (0.028 sq ft each): 14.4 ÷ 0.028 = 515 tiles. Most mosaic tile is sold on 12×12 sheets — 15 sheets (each covering approximately 1 sq ft) covers the 14.4 sq ft needed.
For the wall tile: using 12×24 tile (2.0 sq ft each) for the 101.2 sq ft of wall area: 101.2 ÷ 2.0 = 50.6 — order 51 tiles. If your box has 8 tiles (16 sq ft per box), that is 4 boxes for the walls. Total material budget combines wall tile boxes plus mosaic floor tile sheets plus setting materials.
Shower Tile Tips
Always use a shower-specific waterproofing system, not standard drywall or cement board alone. Water migrates through grout lines and thinset over time. A sheet or liquid waterproofing membrane applied before tile is the only reliable way to prevent water intrusion into the wall cavity, which causes mold, rot, and structural damage that may not be visible for years.
Plan your accent or niche tile before purchasing. A shower niche typically uses the same tile as the surrounding wall but bordered with a pencil liner or different color. The niche floor should slope slightly toward the shower — typically a 1/8-inch pitch — to prevent standing water. Order the niche tile and liner pieces separately so you have the correct quantity for these detailed elements.
Use movement joints (caulk, not grout) at all inside corners and where the floor meets the walls. Tile and substrates expand and contract at slightly different rates. Grout in inside corners cracks within one to two years under these stresses. Filling inside corners with a color-matched, mold-resistant silicone caulk prevents this and is standard practice per ANSI and TCNA installation guidelines.
What to Buy
For shower walls, American Olean, Daltile, and Emser Tile all produce large-format porcelain wall tiles with low water absorption and good bond to thinset. For shower floors, any 2×2 or smaller porcelain mosaic on mesh backing works well — look for COF 0.60+ for wet areas. MSI's stacked stone or glass mosaics are popular for feature walls behind the showerhead.
For setting materials: use Schluter Kerdi-Band and Kerdi membrane for waterproofing, or RedGard as a liquid alternative. Use a white polymer-modified thinset (Laticrete 254 or Custom ProLite) to set wall tile — white thinset prevents show-through on light or glass tile. For the floor, use unsanded grout for mosaic tiles with joints under 1/8 inch, or epoxy grout for the ultimate in mold resistance and durability.
Frequently Asked Questions
How do I calculate tile for a shower? +
Calculate shower walls and floor separately, then add the tile counts together. For each wall, multiply height × width to get the wall area in square feet. Add all wall areas, subtract any window or niche openings, then apply your tile size and waste factor. For the floor, multiply shower length × width and apply a higher waste factor (15%) since the smaller floor area has proportionally more cut tiles at the edges.
What size tile is best for a shower floor? +
Small format tiles — 2×2, 3×3, or 4×4 inch mosaics, or penny round tiles — are best for shower floors. Their small size allows more grout lines, which provide better traction. They also conform to the curved slope (called a "pitch") toward the drain without lippage issues that plague large-format tiles on a sloped surface. For a curbless or "wet room" style shower, use mosaic tiles on the floor and reserve large tiles for the walls.
What tile size is best for shower walls? +
Large-format tiles (12×24, 24×48, or 18×36) are the most popular choice for shower walls in modern bathrooms — fewer grout lines mean a sleeker appearance and less surface area for mold and soap scum to accumulate. Subway tiles (3×6, 4×8, or 4×12) remain a classic choice for their versatility across traditional and contemporary styles. Small mosaic tiles work on walls but require significantly more grout maintenance.
How much extra tile should I add for a shower? +
Add 15% for shower walls — the cuts around the shower niche, valve trim, and the angled cuts at the pan threshold generate more waste than a simple floor or wall tiling job. Add 15 to 20% for the shower floor, especially with small mosaic tiles that require careful cuts at the drain collar and curb edges. Buy one extra sheet of mosaic tile beyond the calculated amount as a repair reserve.
Do I need special tile for a shower? +
Shower floor tile must be rated for floor use with a COF (coefficient of friction) of 0.60 or above for wet areas — this is higher than the 0.50 minimum for dry floors. Shower wall tile does not need a floor rating, but should be porcelain or glazed ceramic with low water absorption. Avoid natural stone on shower floors unless it is honed (not polished), sealed, and resealed regularly — polished stone becomes dangerously slippery when wet.
What is the correct slope (pitch) for a shower floor? +
The standard pitch is 1/4 inch drop per foot toward the drain. A 3 × 3 shower floor needs a total slope of 3/4 inch across the shortest dimension. This slope is why small tiles work better than large tiles on shower floors — a 24×24 tile spanning 2 feet of slope has a 1/2-inch height difference across its length, causing lippage problems and water retention. Small tiles conform to the slope without this issue.
How do I waterproof a shower before tiling? +
The two most common systems are sheet membranes (Schluter Kerdi) and liquid-applied membranes (RedGard, Laticrete Hydro Ban). Sheet membranes require embedding in thinset and are highly reliable but add to installation time. Liquid membranes are brush-applied in two coats and cure in 24 hours. Both must cover all surfaces — floor, walls, and corners — and extend at least 6 inches above the intended water line. The waterproofing is installed before any tile is set.
