Shower Niche Size Calculator
Tile and wall
Niche that fits one stud bay
12.25 in × 12.5 in
- Rough opening (one bay)
- 14.125 in × 14.375 in
- Tiles across / rows up
- 2 / 4
- Clear stud bay
- 14.5 in
- Two bays (stud headered)
- 24.5 in wide, rough 26.375 in
- Build-up per side
- 0.938 in
Measure your actual stud bay before cutting; old houses and metal studs vary.
Tools the pros use for this job
Preformed Niche
Hard-To-Find Fastener Phillips Self-Piercing Cement Board Screws, Durable Steel Hardware Fasteners for Home Improvement, DIY, Construction, 8 x 1-1/4, Pack of 157
$10.49
Check price on AmazonWaterproof foam niches drop into a stud bay; check the rough size against the result above.
Waterproofing
Hard-To-Find Fastener Phillips Self-Piercing Cement Board Screws, Durable Steel Hardware Fasteners for Home Improvement, DIY, Construction, 8 x 1-1/4, Pack of 157
$10.49
Check price on AmazonEvery inside corner of a niche needs the membrane lapped and sealed.
Edge Trim
White Caulk Tape Waterproof Self Adhesive, Toilet & Bathtub Sealant Strip, Peel & Stick Caulking Tape for Floor Tile Corner Trim & Shower, Bathroom Accessories, Better Than Silicone Caulk
$9.98
Check price on AmazonMetal trim finishes the niche edges when you would rather not miter tile.
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Prices as of Sep 30, 2026, 4:37 AM UTC. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
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How this calculator works
Stud bay. Wall studs sit 16 in or 24 in apart, measured centre to centre, and a 2x stud is 1-1/2 in thick. The clear space between two studs is the spacing minus 1-1/2 in: 14-1/2 in at 16 in on centre, 22-1/2 in at 24 in. A niche wider than that needs the middle stud cut and a header and sill framed in, which gives two bays less one stud: 30-1/2 in at 16 in on centre.
Tile alignment. The finished opening is a whole number of tile-plus-joint modules, so the niche edges fall on grout-line centres and the field tile runs straight into it. With 3x6 subway laid flat and a 1/8 in joint, one module is 6-1/8 in across and 3-1/8 in up.
Rough opening. The framed hole is bigger than the finished niche by the wall build-up on both sides: backer board, thinset and the tile that wraps the returns. With 1/2 in board, 1/8 in thinset and 5/16 in tile that is 15/16 in a side, so a 12-1/4 in finished niche needs a 14-1/8 in rough opening, which fits the 14-1/2 in bay.
Slope the niche sill slightly toward the shower so water drains out, and waterproof the whole box, including every inside corner, before tiling.
Frequently asked questions
What is a standard shower niche size?
There is no code size. Many niches are built to fit one stud bay, which at 16 in on centre leaves 14-1/2 in of clear width before board and tile, so the finished opening usually ends up around 12 in wide. Height is a design choice; 12 in fits most bottles, and a taller niche can take a shelf.
How wide can a shower niche be between studs?
At 16 in on centre the bay is 14-1/2 in wide. Take off the board, thinset and tile on both sides, typically about 1-3/4 to 2 in in total, and the finished width is about 12-1/2 in or less. Wider niches need a stud cut and headered.
How do I line a niche up with my tile?
Make the finished width and height whole multiples of the tile plus one grout joint, and set the niche so its edges fall on grout lines. The calculator does this for the tile and joint you enter.
Can a niche go on an exterior wall?
It is usually avoided, because cutting into the insulated cavity leaves a cold spot where condensation can form behind the niche. Put niches on interior walls where you can.
Should the bottom of a niche slope?
Yes, slightly toward the shower, so water does not pool on the sill. Waterproof the niche fully before tiling.
Related calculators
- Tile Layout & Pattern CalculatorCut sizes and row counts for grid, offset, diagonal, herringbone.
- Shower Tile CalculatorWalls, floor, curb, and niche for a full shower surround.
- Deck Mud CalculatorSloped shower pan mortar bed: cubic feet and bags for centre or linear drains.
- Backer Board CalculatorCement board sheets, screws, and tape for floors and walls.
- Subway Tile Calculator3x6 subway tile counts by pattern for walls and backsplashes.
Guides worth reading next
- How to Measure a Room for Tile (Step by Step)Measure any room for floor or wall tile: handle closets and alcoves, convert inches to decimals, subtract fixtures, and add the right waste percentage.
- Choosing the Right Tile Size for Your RoomHow tile size changes a room: when 12×24 beats 4×4, why small rooms can take large tile, grout line math, and the flatness rule for big formats.
- Sanded vs Unsanded vs Epoxy Grout: Which One Do You Need?Grout types explained by joint width and location: when sand scratches tile, why epoxy wins in showers, and how much of each type a bag actually covers.