Shower Tile Calculator

A shower tile calculator works out how many wall tiles you need to line a shower or tub surround, with a generous waste allowance because wet-area tiling has more cuts — around the niche, the valve, the corners and the curb. Enter the wall area (or one wall's dimensions) and your tile size.

Your measurements

Result

The tiling maths is the same as any wall, but a shower is unforgiving about what's behind the tile: it must be waterproofed (a cement backer board or a membrane) or it will rot. The shopping list reflects that.

How it is calculated

Tiles = wall area divided by the area of one tile, times one plus the waste percentage, rounded up. We default to 15% waste — higher than a plain floor — because showers have many cuts around fixtures, niches and corners. The calculator sizes tile only; waterproofing and setting materials are separate.

Steps

Add up the area of all the walls you're tiling, or enter one wall to start.
Enter your tile size — large-format and subway tiles are common in showers.
Keep the waste at 15% — shower cuts add up fast.
Read the tile count and round up to full boxes.
Buy backer board or a waterproof membrane for behind the tile.

Worked example

A shower with 120 sq ft of wall and 12 × 24 in tiles (2 sq ft each) at 15% waste needs 69 tiles.

Common questions

How many tiles for a shower?

Divide the total wall area by the area of one tile and add 15% for cuts. The calculator rounds up to whole tiles.

Do I need waterproofing behind shower tile?

Yes — a cement backer board or a waterproof membrane (e.g. a sheet system) behind the tile is essential, or moisture will rot the wall.

How much waste should I allow?

About 15% for a shower because of all the cuts around niches, valves and corners — more for small mosaics or a busy layout.

What size tile is best for a shower?

Larger tiles mean fewer grout lines to seal; small mosaics conform to curves and floors. Both work — just match the waste and grout to the tile.