By Zach Wennstedt, owner of Aging Safely Baths. We sell and install all three types nationwide. Updated October 2026.
Families usually call us with one of three words: roll in, transfer or curbless. They get used like they mean the same thing. They do not, and picking the wrong one is expensive, because the bathroom gets torn out a second time. Here is the plain-English difference, with the real dimensions.
Roll in shower: large enough to roll a wheelchair or shower chair inside. Threshold is a small beveled lip, half an inch or less in ADA versions.
Transfer shower: a compact 36 x 36 inch stall with a seat. The person stops a wheelchair outside and slides across onto the seat.
Curbless shower: no curb at all. The floor slopes to a drain. It usually means recessing the subfloor or building up the bathroom floor.
If someone uses a wheelchair full time, or may soon, think roll in. If they can stand and pivot with help, a transfer shower can work in a smaller space.
Side by side
| Roll in shower | Transfer shower | Curbless shower | |
|---|---|---|---|
| Who it fits | Full-time wheelchair users, rolling shower chairs, caregiver-assisted bathing | People who can transfer from a wheelchair or walker to a seat | Anyone, when the floor can be rebuilt |
| ADA minimum size | 30" x 60" (alternate: 36" x 60") | 36" x 36" (exactly, inside) | Not an ADA category by itself |
| Threshold | 1/2" max, beveled (ADA) | 1/2" max (ADA); many home models are higher | None |
| Seat | Optional fold-up seat | Required in ADA version | Optional |
| Floor work | Usually none with a low-threshold pan | Usually none | Often major: recess or build up the floor |
| Fits a 60" tub space | Yes, the most common swap | Needs a 36" x 36" area | Depends on the floor |
ADA dimensions from the 2010 ADA Standards, section 608 (U.S. Access Board). Homes are not required to meet ADA, but the ADA sizes are a proven starting point.
Roll in showers
A roll in shower is the most common accessible shower we install, mostly because it drops right into the space where an old 60 inch bathtub was. A one-piece or multi-piece pan with a low beveled threshold means a wheelchair, a rolling shower chair or a walker can come straight in. See our handicap and roll in showers and the roll in shower dimensions guide.
- Best for: full-time wheelchair users, people who need a caregiver to help them bathe, and anyone planning to stay in the home as mobility changes.
- Common sizes: 60 x 30, 60 x 33 and 60 x 36 inches for a tub swap; 63 inch models for ADA layouts; 48 inch models for smaller spaces.
- Watch for: water control. With a very low threshold, the pan slope, a collapsible water dam and a weighted curtain matter. A good installer sets the pan level and sloped correctly.
Transfer showers
A transfer shower is built for sliding across. The ADA version is exactly 36 by 36 inches inside, with a seat on the wall opposite the controls and grab bars placed for the transfer. Because it is so compact, it can fit where a 60 inch roll in will not, like a small hall bath or a converted closet. See our 40 x 38 ADA transfer shower and the code compliant showers.
- Best for: people who can stand and pivot, or slide sideways, with or without help.
- Not ideal for: someone who will need to stay in a wheelchair or shower chair while bathing. A rolling chair does not fit inside a 36 x 36 stall with a caregiver.
- Tip: if mobility is likely to decline, a roll in shower is usually the safer long-term choice.
Curbless showers
Curbless means no curb or lip at all. The bathroom floor itself slopes to a linear or center drain. It looks great and has no lip to catch a wheel. The catch is the floor. To get the slope without a curb, the subfloor usually has to be recessed between the joists, or the rest of the bathroom floor raised. On a concrete slab, that can mean cutting concrete. That is why curbless projects take longer and cost more than a roll in pan with a low beveled threshold.
For most homes, a roll in shower with a low beveled threshold gets you nearly all the benefit of curbless, installed in a day instead of a week.
How to decide in 4 questions
- Will the person bathe while seated in a wheelchair or rolling shower chair? If yes, roll in.
- Can they stand and pivot to a seat? A transfer shower can work, especially in a small room.
- Will a caregiver help? Plan for a roll in with room for the caregiver at the side.
- What is under the floor? On a slab, a low-threshold roll in pan is usually far simpler than curbless.
Think 3 to 5 years ahead. A bathroom should fit the person's mobility today and later, so it never has to be redone. That is also why we always send a tech for a site visit before install: the floor, the drain location and the doorways decide what will really work.
Features that matter in all three
- A handheld shower on a slide bar, with a hose at least 59 inches long (the ADA length).
- A pressure-balancing or thermostatic valve to limit scald risk.
- Grab bars where the person actually transfers, not just where they look tidy.
- A fold-up or fixed seat at a comfortable height.
- Slip-resistant textured floor.
Related reading: roll in shower vs. walk in shower, handicap shower installation cost, and setting up a bathroom for a caregiver.
Call 1-888-779-2284 (7 days, 7am to 8pm MT) or request your price range. No high-pressure sales pitch. Once you pick your unit, a tech visits your home before install day.
Frequently asked questions
What is the difference between a roll in shower and a transfer shower?
A roll in shower is large enough to roll a wheelchair or shower chair inside, with an ADA minimum of 30 by 60 inches and a threshold of half an inch or less. A transfer shower is a compact 36 by 36 inch stall where the person stops outside and slides onto a built-in seat.
Is a curbless shower the same as a roll in shower?
Not exactly. A curbless shower has no curb at all and usually needs the floor recessed or rebuilt. Most roll in showers use a pan with a very low beveled threshold, which gives nearly the same easy entry without major floor work.
What size is an ADA transfer shower?
Under the 2010 ADA Standards, a transfer shower is exactly 36 by 36 inches inside, with a seat and grab bars.
What size is an ADA roll in shower?
The ADA standard roll in shower is at least 30 inches wide by 60 inches long; the alternate roll in shower is at least 36 by 60 inches.
Which accessible shower fits where my bathtub is?
A 60 inch roll in shower is the most common replacement for a standard 60 inch bathtub, and it can usually be installed in one day.