Published August 14, 2026 · Updated August 23, 2026 · By Tupep
A shower is four separate takeoffs
The reason shower tile orders come up short is that people multiply the wall area, add ten percent, and call it done. A shower has four surfaces with completely different geometry, and each one wastes tile at a different rate. The walls are big flat planes with clean cuts. The pan is sloped in four directions at once. The niche is five tiny surfaces with twenty cuts. The curb is three narrow strips that all have to meet at a mitered corner.
We estimate a surround as three separate takeoffs rather than one, because the three surfaces do not share a waste factor. Wall field tile cuts cleanly around a rectangle and runs lean. The floor is mosaic on a sloped plane with a drain in the middle of it, and every sheet gets trimmed. The niche is almost entirely edge work. Averaging them into one percentage leaves you short on exactly the pieces that are hardest to re-order in a matching lot.
Run them as four line items. The total will be higher than the single number you had in mind, and it will be right.
The formula
Order = sum over each surface of (surface area x its own waste factor)
Surface areas, for an alcove shower:
- Walls = (back width + 2 x side depth) x tile height, minus niche opening
- Pan = width x depth
- Niche = back panel + 2 sides + top + bottom, using the framed depth
- Curb = top face + outside face + inside face, each at the curb length
Worked example: 60 by 32 inch alcove, tile to 84 inches
Niche is 14 inches wide by 22 inches tall, framed 3.5 inches deep. Curb is 4.5 inches wide on top, 6 inches tall outside, 4 inches tall inside.
| Surface | Calculation | Area (sq ft) | Waste | Order (sq ft) |
|---|---|---|---|---|
| Back wall | 60 x 84 / 144 | 35.00 | 10% | 38.5 |
| Two side walls | 2 x (32 x 84) / 144 | 37.33 | 10% | 41.1 |
| Less niche opening | 14 x 22 / 144 | -2.14 | 10% | -2.4 |
| Curb, three faces | 60 x (4.5 + 6 + 4) / 144 | 6.04 | 20% | 7.2 |
| Shower pan | 60 x 32 / 144 | 13.33 | 15% | 15.3 |
| Niche interior | (14×22 + 2x22x3.5 + 2x14x3.5) / 144 | 3.89 | 30% | 5.1 |
Adding the wall tile items: 38.5 + 41.1 – 2.4 + 7.2 = 84.4, so order 85 square feet of wall tile. Adding the mosaic items, since the pan and the niche interior in this build are both 2×2 mosaic: 15.3 + 5.1 = 20.4, so order 21 square feet of mosaic.
Sanity check the niche math. Back panel is 14 x 22 = 308 square inches. Two sides are 22 x 3.5 = 77 each, 154 total. Sill and head are 14 x 3.5 = 49 each, 98 total. Sum is 560 square inches, divided by 144 is 3.89 square feet. Under four square feet of tile, and it will take you longer than the back wall.
Why the waste factors differ that much
| Surface | Waste | What drives it |
|---|---|---|
| Walls | 10% | Straight cuts, offcuts reusable at the opposite corner |
| Curb | 20% | Narrow rips, mitered ends, two cuts per piece |
| Pan | 15% | Sheets cut around the drain, wedge cuts at the slope changes |
| Niche | 30% | Five small planes, no offcut is big enough to reuse |
On the pan, mosaic sheets get sliced into strips to follow the slope changes running from each corner to the drain. Those diagonal breaks eat sheets. Around the drain itself you will cut a square hole out of the middle of a sheet and throw away four corners.
Detailing the niche and the curb
The single best thing we do on a shower is size the niche to the tile before it gets framed. If the field tile is 3×6 on a 1/16 joint, a niche opening of 12-1/8 inches wide takes exactly two tiles across with no rips. Frame to the tile and the niche looks built in. Frame to a round number and every course inside it is a custom cut.
Two more niche details worth the effort. Slope the niche sill outward, commonly about 1/8 to 1/4 inch across the depth, so water runs back into the shower instead of standing on the sill. And run the sill piece so its outer edge overhangs slightly and gets a bullnose or a mitered return, because a raw cut edge at the sill is the first thing that chips.
The curb top wants a slight pitch back into the shower for the same reason. Miter the outside top corner where the top face meets the outside face rather than butting a cut edge against a glazed face. A miter takes an extra ten minutes and it is the difference between a curb that looks fabricated and one that looks assembled.
Waterproofing, slope and coverage
This is the part of a shower that is code and manufacturer governed, and it varies. Continuous waterproofing behind the tile is commonly required, whether that is a sheet membrane, a liquid applied membrane, or a bonded foam board system. Slope to the drain is commonly specified at 1/4 inch per foot. The niche, the curb, and every seam and corner are part of the waterproofing envelope, and the drain type has to match the system. Check your local code and follow the membrane manufacturer’s written instructions, because mixing brands or skipping a preformed corner is how warranties get voided.
Mortar coverage in a shower is also held to a higher bar than a dry floor. Near full contact behind the tile is commonly specified for wet areas, typically stated as 95 percent, and hollow spots behind a shower wall tile are where the trouble starts. That means back buttering, not just combing the wall.
- Walls, 3×6 tile: 1/4 x 3/8 square notch, roughly 85 to 95 sq ft per 50 lb bag, less with back buttering.
- Pan, 2×2 mosaic: a 3/16 or 1/4 inch V notch, so the sheet can be beaten flat without mortar squeezing up through the joints.
- Use a non sag wall mortar on the verticals. Standard floor thin set will let a heavy wall tile creep down the wall while you work.
Pull one wall tile early and look at the back before you have thirty of them set. That five second check has saved us from tearing out entire walls.
Related guides
- Large Format Tile: Why 10% Waste Is Not Enough
- Diagonal vs Straight Lay: How Layout Changes Waste Factor
- Subway Tile Backsplash: How Many Square Feet for a Kitchen
- Grout for Large Format Tile
Sources and Further Reading
Run your own numbers with the Tile Calculator, or browse every tool on the calculators index. Coverage figures and material constants are cross-checked against manufacturer technical data sheets before publication. See our Methodology page for how figures are selected and verified.
Planning estimate only. Results assume standard conditions and are intended for material planning. Verify against your product’s technical data sheet and your local building code before purchasing. Structural, electrical, and gas work should be specified by a licensed professional.
Last updated: August 23, 2026
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