Shower Tile Calculator: How Much Tile Do You Need for a Shower?

I'll be honest with you: my first shower tile job, I ran short by half a box. Same tile, different dye lot, and you could see the shade difference every single morning for three years. Don't be me. Measure twice, buy once.

Measure your walls (the boring part that matters)

Grab a tape measure and get the width and height of every wall you're tiling. A standard alcove shower has three walls. Write them down — don't trust your memory on this.

Say you've got a typical 60" × 32" alcove, tiling up to 80":

• Back wall: 60 × 80 = 4,800 sq in
• Two sides: 32 × 80 × 2 = 5,120 sq in
• Total: 9,920 sq in ÷ 144 = about 69 sq ft

That's your starting number. Everything else adjusts from here.

What to subtract (less than you'd think)

Here's what beginners get wrong — they start subtracting every little thing. Don't. The shower valve? Tiny. The showerhead? Leave it. You're grouting around them, not cutting tile to fit like a jigsaw puzzle.

The one thing worth thinking about: the niche. A standard 12" × 12" niche is 1 sq ft of wall you won't tile — but then you tile inside the niche, which adds roughly 2 sq ft back. So honestly? Just call it a wash and don't subtract anything. I've done it both ways and the difference is a rounding error.

Working number: ~69 sq ft.

The waste factor (this is where showers punish you)

Showers are brutal on tile waste. You've got corners on every wall, cuts around the niche, and if you're tiling the floor too, the slope to the drain means a ton of little angled cuts.

Here's what I'd actually add:

• Big tiles (12×24): 15% — those long cuts along walls eat tile
• Small mosaics: 10% — they're forgiving
• Diagonal or herringbone: 20%, no debate. I don't care how good you are at math, diagonal layouts generate offcuts like crazy.

For our 69 sq ft with 12×24 tile: 69 × 1.15 = 80 sq ft.

Boxes never divide evenly (annoying but true)

Tile comes in boxes of, say, 15 sq ft. 80 ÷ 15 = 5.33 boxes. You can't buy a third of a box, so that's 6 boxes.

And here's my rule: keep one unopened box in the garage. If a tile cracks in two years, you'll thank me. Stores discontinue lines constantly.

The stuff people forget

Grout: A 25 lb bag (Mapei or Custom Building Products, ~$15-20 at Home Depot) covers about 100 sq ft of large tile. One bag. Done.

Thinset: Walls are thirsty. A 50 lb bag covers maybe 75 sq ft on walls — I'd grab two bags for a standard shower. Running out of thinset mid-wall is a special kind of misery.

Waterproofing: This is the big one. Tile isn't waterproof — the membrane behind it is. Paint-on stuff like RedGard (~$55/gallon) or a sheet membrane like Schluter Kerdi. Skip this and your "beautiful tile job" becomes a mold farm in 18 months. I'm serious about this one.

Real numbers for common showers

| Shower | Wall area | With waste | What to buy | |---|---|---|---| | 36" × 36" corner | ~45 sq ft | ~52 sq ft | 4 boxes | | 60" × 32" alcove | ~69 sq ft | ~80 sq ft | 6 boxes | | Big walk-in 60" × 42" | ~85 sq ft | ~98 sq ft | 7 boxes |

(Assuming 15 sq ft boxes and 15% waste — adjust for your tile.)

Want me to do the math for your exact shower? Punch your numbers into our free tile calculator and it'll handle the waste calc for you.