Standard Shower Dimensions
Common stalls run 32 × 32 in to 36 × 36 in; walk-ins start at 60 × 30 in. Enter a finished inside size to check it against the code minimums.
Reference table
Standard Shower Sizes and Stall Dimensions
Nominal sizes that shower bases and tubs are sold in, width along the entry × depth. Small showers start at the code minimum.
| Shower | Size | Metric | Floor area | Good to know |
|---|---|---|---|---|
| Code minimum | 30 × 30 in | 76.2 × 76.2 cm | 900 sq in | Smallest square the IRC allows |
| Small stall | 32 × 32 in | 81.3 × 81.3 cm | 1,024 sq in | Meets the UPC’s 1,024 sq in |
| Square stall | 36 × 36 in | 91.4 × 91.4 cm | 1,296 sq in | The size the NKBA recommends |
| Rectangular stall | 48 × 36 in | 121.9 × 91.4 cm | 1,728 sq in | Comfortable for one person |
| Neo-angle corner | 36 × 36 in to 42 × 42 in | 91.4 × 91.4 cm to 106.7 × 106.7 cm | Less than the square | The clipped front corner takes floor |
| Tub-shower | 60 × 30 in or 60 × 32 in | 152.4 × 76.2 cm or 152.4 × 81.3 cm | 1,800 sq in or 1,920 sq in | Outside tub size; the inside is smaller |
Finished inside sizes can be a little smaller than a base’s nominal size once wall panels, tile and a curb go in, so measure the built shower before you rely on a number.
Standard Walk-In Shower Sizes and ADA Dimensions
Walk-in bases are long and shallow. ADA sizes are the rules for public buildings, listed as a reference for accessible design at home.
| Shower | Size | Metric | Floor area | Good to know |
|---|---|---|---|---|
| Alcove walk-in | 60 × 30 in | 152.4 × 76.2 cm | 1,800 sq in | Kohler’s average US walk-in |
| Walk-in | 60 × 36 in | 152.4 × 91.4 cm | 2,160 sq in | A common tub-to-shower size |
| Large walk-in | 60 × 42 in | 152.4 × 106.7 cm | 2,520 sq in | For larger bathrooms |
| ADA transfer | 36 × 36 in | 91.4 × 91.4 cm | 1,296 sq in | 36 in entry across the front |
| ADA roll-in (minimum) | 60 × 30 in | 152.4 × 76.2 cm | 1,800 sq in | 60 in entry on the long side |
| ADA alternate roll-in | 60 × 36 in | 152.4 × 91.4 cm | 2,160 sq in | 36 in entry at one end |
ADA sizes are clear inside dimensions measured at the center points of opposing sides (2010 ADA Standards 608.2), with the entry along the width. A transfer shower also needs a clear space of 36 × 48 in in front; a roll-in, 30 × 60 in along its open face.
Minimum Shower Dimensions by Code
The model code rules most US homes are checked against. Your state or city may amend them, and the inspector has the final say.
| Rule | Minimum | Metric | Good to know |
|---|---|---|---|
| Floor area (IRC) | 900 sq in | 0.58 m² | Inside the finished walls |
| Narrowest side (IRC) | 30 in | 76.2 cm | So 30 × 30 in is the smallest square |
| Narrow exception (IRC) | 25 in with 1,300 sq in | 63.5 cm with 0.84 m² | For example 25 × 52 in |
| Door or entry (IRC) | 22 in clear | 55.9 cm | Hinged doors open outward |
| Clear floor in front (IRC) | 24 in | 61 cm | 21 in in front of a tub |
| Height the size holds (IRC) | 70 in above the drain | 177.8 cm | Valves, soap dishes and grab bars excluded |
| UPC 408.6 | 1,024 sq in + 30 in circle | 0.66 m² + 76.2 cm | California and other UPC states |
| NKBA recommendation | 36 × 36 in, 30 in clear | 91.4 × 91.4 cm, 76.2 cm | A design guideline, not code |
IRC: 2021 and 2024 International Residential Code, P2708.1, P2708.1.1 and Figure R307.1. UPC 408.6: Uniform Plumbing Code, adopted in California as CPC 408.6. NKBA: Bathroom Planning Guidelines. Metric figures are conversions at 2.54 cm per inch.
Check More Than the Shower’s Area
Measure Inside the Finished Walls
Codes measure the finished inside: tile face to tile face, and from the back wall to the middle of the threshold. Base sizes are nominal, and wall panels, tile and a curb all take space, so measure the shower you will stand in.
Enter Your Inside SizeCheck the Width Rule, Not Just the Area
The IRC asks for 900 sq in of floor and 30 in in the narrowest direction. A 40 × 24 in shower has 960 sq in and still fails. Narrower showers down to 25 in pass only with 1,300 sq in or more.
Test a Narrow ShowerLeave Clear Floor in Front
Fixture spacing rules ask for 24 in of clear floor in front of a shower opening and 21 in in front of a tub; the NKBA recommends 30 in. The plan draws that strip, so you can see how much floor the shower really takes.
See the Clear FloorCompare Shower Types and Sizes
Pick a stall, walk-in or tub-shower size and the checker runs the same rules on each, adds the 1,024 sq in test used in California and compares it with the ADA transfer and roll-in sizes for public buildings.
Try the Tub-Shower SizeHow to Take Shower Measurements
A tape measure and the checker above are all it takes.
- 1
Measure the finished inside
Measure tile face to tile face along the entry, then from the back wall to the middle of the threshold. Skip valves, soap dishes and grab bars; the code does not count them.
- 2
Enter the width and depth
Type both sizes in inches or centimeters, or start from a common stall, walk-in or tub-shower size and adjust it to what you measured.
- 3
Read both rules and the clear floor
Check the area and narrowest-side rows, then the clear floor in front. The result is a planning aid: your local code and your inspector decide.
When Shower Dimensions Matter
Swapping a tub for a shower
Shower bases come in the same 60 × 30 in and 60 × 32 in sizes as alcove tubs, well above the code minimum. Re-check the depth once the new wall panels are on.
Fitting a shower into a small bathroom
Every shower needs its footprint plus 24 in of clear floor in front. Check the shower here, then work out the room’s total floor area.
Choosing finishes for a new shower
Settle the size first, then preview tile, fixtures and glass on a photo of your own bathroom before you order.
FAQ
Questions About Shower Sizes
Common stalls are 32 × 32 in or 36 × 36 in, and rectangular stalls 48 × 36 in. Walk-in bases usually run 60 × 30 in to 60 × 42 in, and tub-showers follow alcove tubs at 60 × 30 in or 60 × 32 in. These are nominal sizes; the finished inside can be a little smaller.
Under IRC P2708.1 a shower needs at least 900 sq in of floor and at least 30 in in its narrowest direction, so 30 × 30 in is the smallest square. Places on the Uniform Plumbing Code, such as California, ask for 1,024 sq in and room for a 30 in circle, which makes it 32 × 32 in.
30 in, measured inside the finished walls at the top of the threshold. The IRC allows down to 25 in only when the floor is at least 1,300 sq in, for example 25 × 52 in. The door or entry needs at least 22 in of clear width.
Kohler puts the average US walk-in at 60 × 30 in and suggests 60 × 42 in for larger bathrooms; 60 × 36 in bases are a common tub-to-shower choice. Kohler calls 36 × 36 in the smallest recommended walk-in, and 48 × 36 in comfortable for one person.
The IRC’s fixture spacing figure asks for 24 in of clear floor in front of a shower opening and 21 in in front of a tub. The NKBA recommends 30 in. So a 36 × 36 in shower takes a 36 × 60 in strip of floor.
There is no single number; add up the fixtures. The smallest shower is 30 × 30 in plus 24 in of clear floor in front, a 30 × 54 in strip. A toilet needs 15 in from its center to each side and 21 in of clear floor in front, and so does a sink.
An ADA transfer shower is 36 × 36 in inside with a 36 in entry; a standard roll-in is at least 60 × 30 in with a 60 in entry along the long side. The 2010 ADA Standards cover public buildings; in a home they are a guide for accessible design.
No. It applies the IRC and UPC size rules to the rectangle you enter. Your local code, its amendments and your inspector decide, and they also check what this page cannot, such as the door, drain, waterproofing and any bench or niche.