Shower Tile Calculator: How Much Tile Do You Need?

Before calculating tile, you need your shower dimensions. Here are the three most common pre-set shower sizes used in residential construction. All wall calculations assume 8-foot (96-inch) ceiling height with tile running floor to ceiling on all three walls.

Not sure which size applies to you? Measure your shower opening width (the wall with the door or curtain) and the depth (side walls). The 60" × 32" size is common for tub-to-shower conversions, while 36" × 36" is typical for corner showers.

Most showers have three tiled walls — one back wall and two side walls. The fourth side is the door or curtain opening. Here's how to calculate the total wall tile area:

For showers that don't tile all the way to the ceiling, replace the 8-foot ceiling height with your actual tile height. Many designs tile to 7 feet or just above the showerhead (approximately 84 inches).

If your shower has a half-wall or pony wall (common in walk-in showers), calculate that wall separately: width × half-wall height. Add it to your total and remember to tile both sides of any freestanding half-wall.

Shower floor tile is calculated separately from wall tile because it typically uses a different tile size and style. The formula is straightforward:

Why Shower Floors Use Smaller Tiles

Shower floors must slope toward the drain (typically ¼ inch per foot). Smaller mosaic tiles — usually 1×1 inch or 2×2 inch — conform to this slope much better than large-format tiles. The additional grout lines also provide critical traction on wet surfaces.

Pre-Slope and Drain Cutout

The shower floor is built on a pre-slope (mortar bed) that directs water to the drain. When calculating floor tile, do not subtract the drain area — the small circular cutout (typically 4" diameter) is negligible and accounted for in your waste factor. However, if using a large linear drain (12–36" long), subtract approximately 0.25–0.5 sq ft from your floor total.

Shower Niche Calculation

A shower niche (recessed shelf) has five interior surfaces that all need tile. Here's the breakdown for a standard niche measuring 12" wide × 14" tall × 3.5" deep:

Shower Curb / Threshold

The shower curb is the raised barrier at the shower entrance that keeps water contained. A standard curb has three tile surfaces: the front face, the top, and the back face.

Ceiling Option

If you plan to tile the shower ceiling (recommended for steam showers), the area is the same as the floor: width × depth. For a 48" × 36" shower, that adds another 12 sq ft. Use the same tile as the walls for a seamless look, or choose a lighter color to prevent the space from feeling closed in.

Tile itself is not waterproof — the waterproofing membrane behind the tile is what protects your walls and subfloor. Waterproofing is a critical step that affects how your tile adheres and how long your shower lasts.

Common Waterproofing Systems

How Waterproofing Affects Tile

Waterproofing membranes add a thin layer (1–3mm) to your wall surfaces. This is important for two reasons:

• Modified vs. unmodified thin-set: Some membranes require unmodified thin-set (like Kerdi), while others need modified. Using the wrong type causes bond failure.
• Seam overlap: Plan for 2-inch minimum overlap at all seams and 4-inch overlap at corners. This doesn't change tile quantity but affects layout planning.
• Cure time: Liquid membranes need 24–72 hours to cure before tiling. Factor this into your project timeline.

Let's walk through a full tile calculation for a 48" × 36" shower with 8-foot ceilings, one standard niche, and a curb:

Adding Waste Factors

• Measure your shower at least twice before ordering. Measure at three heights (bottom, middle, top) as walls may not be perfectly plumb
• Order all tile from the same lot number to ensure consistent color. Tiles from different production runs can vary noticeably
• Plan niche placement between studs (standard 14.5" opening). Decide niche location before framing so you don't cut structural members
• Keep 5–10% of leftover tile for future repairs. Store it flat in a dry area with the lot number noted

• Start wall tile from the center and work outward for symmetrical cuts on both edges. Avoid slivers (less than half a tile width) at corners
• Install floor tile before wall tile so the wall tile overlaps the floor edge, directing water down and onto the floor rather than behind it
• Use silicone caulk (not grout) at all change-of-plane joints — where walls meet floors, walls meet walls, and walls meet the ceiling
• Slope the niche shelf slightly outward (about 1/16") so water drains out instead of pooling inside
• Use epoxy grout in showers for superior water and mold resistance — it costs more but lasts significantly longer than cement-based grout