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Step-In Threshold Heights by Model and How Low It Can Go

Updated September 2026

▶Glossary5
  1. Thresholds by Model
  2. Lowering the Threshold
  3. Threshold vs Door Opening vs Seat Height
  4. Related Guides
  5. Common Questions

The step-in threshold height on an Ella walk-in tub is the low lip you cross at the door, and depending on the model and how the drain is installed it runs from about 3.5 to 7 inches, compared with the roughly 18 to 22 inch wall of a standard bathtub. Published drawing values and the figures our team gives are listed below; if the threshold is critical for the bather, ask the team for your exact model's figure in writing before ordering.

Large man stepping into the Ella Big4One walk-in tub over its low step-in threshold through the outward swing door
Stepping over the Big4One's threshold, roughly 5 inches, through the outward U-shape door.

Thresholds by Model

  • Monaco: 3 5/8 in (technical drawing). Mobile: about 3 3/4 in (drawing).
  • Transfer32: about 4 to 4.5 in per our team.
  • Big4One: about 5 in. ShaK: about 5 in. Ultra: about 6 in. Elite: about 6.5 in (figures given by our team).
  • General guidance from our team: most in-swing tubs land around 4 to 5 in and some outward-swing tubs around 6 in. The Transfer family and the Capri are among the lowest at roughly 3.5 to 4 inches.
  • Legacy S-Class: 6 in standard or 3 in low-threshold versions.

Lowering the Threshold

Thresholds can be reduced to about 3 to 3.5 inches when the tub is set lower and the drain body sits below the subfloor. The leveling legs let the tub sit lower, but the drain then needs a subfloor opening, and the bottom of the apron or end panel is trimmed to clear the floor. Cutting those parts voids warranty coverage on the altered panels only, so plan it with your installer and read lowering the tub and recessed installations first. The S-Class 3 inch version was built this way and always required subfloor drain access.

Ella's S-Class Walk-In Tubs with Easy Entry and Textured Floor for Seniors
Chapters in this video
  1. 0:00 S-Class Tub Features Ella's S-Class walk-in tubs feature a low threshold, textured floor, and a sturdy stainless steel frame.
  2. 0:46 Innovative Jetting Design Ella's walk-in tubs are known for their innovative jetting design, including hydro and air massage systems.
  3. 1:26 Faucet Sets and Safety Features Customers can choose from various fast-fill faucet sets, and the tubs include grab bars and a secure door latch for safety.
  4. 1:50 Optional Accessories for Comfort Ella's offers several accessories like a heated seat, glass screen, and support pillows for enhanced comfort.

Watch: Ella's S-Class Walk-In Tubs with Easy Entry & Textured Floor for Seniors with chapters and a full transcript.

This legacy S-Class video is the clearest illustration of how threshold height and drain placement are linked. The S-Class came with a 3 inch low threshold, where the frame was lowered to the floor and the drain needed subfloor access, or a 6 inch standard threshold, where the frame was raised so the drain could pass beneath the tub above the floor. The 6 inch models had jets in the floor, while the low-threshold models had their jets raised off the floor, and the video stresses that the leveling legs are crucial for door alignment. The same trade-off applies to current models. See the S-Class legacy series for that lineup.

Threshold vs Door Opening vs Seat Height

  • Door openings run about 19 to 20 inches wide on U-shape doors (19 1/4 in clear on the Monaco and Mobile drawings); L-shape Transfer doors open the full side. Published widths and arcs are in door opening widths and swing arcs by model.
  • Seat heights target the 17 to 19 inch range used for accessible toilets; the Ultra's 17 inch seat height is called out as ADA-compliant on its spec sheet.
  • Outward doors also need floor clearance in front (about 21 in for the U-shape, 36.5 in for the L-shape), which is separate from the step-in height. See outward door swing clearance.
The Ultra Walk-In Tub with Door and Seat for Elderly and Handicapped
Chapters in this video
  1. 0:00 Introducing The Ultra Walk-In Tub The Ultra walk-in tub is presented, highlighting its durable acrylic, low threshold, textured floor, and frameless door with a frosted glass panel.
  2. 0:31 ADA Compliant Seat And Soaking Depth The tub's ADA compliant seat height and length are detailed, along with how the soaking depth is determined and its specific measurement for the Ultra.
  3. 1:04 Interior Space And Jetting Options The Ultra's interior dimensions are shown, along with available air massage, hydro massage with an inline heater, calf jets, ozone sterilization, and an independent foot massage.
  4. 2:18 Faucets, Drains, And Comfort Features The fast-fill faucet set, dual drain technology, control options, LED chromotherapy, heated backrest, and optional glass screen and rain head shower column are presented.

The Ultra video ties the numbers together for one model: a frameless brushed aluminum inward door, an ADA-height 17 inch seat, a 19 inch seat length, a 17.5 inch soaking depth, a 42 inch interior length and 24 inches of shoulder width, plus the reversible extension panel for a 60 inch alcove and magnetic access panels for service. The Ultra profile has the full spec. Watch: The Ultra Walk-In Tub with Door & Seat for Elderly & Handicapped with chapters and a full transcript.

Senior woman stepping into the Ella Mobile walk-in tub over its low threshold through the outward swing door
The Mobile drawing shows one of the lowest thresholds in the line at about 3 3/4 inches.

Common Questions

Which Ella tub has the lowest step-in?
Among current models, the Monaco and Mobile technical drawings show the lowest thresholds, at 3 5/8 inches and about 3 3/4 inches respectively. The Transfer family and the Capri follow closely in the roughly 3.5 to 4 inch range, which is one reason the Transfer tubs are the usual choice for wheelchair users. Setting the tub lower with the drain recessed below the subfloor can bring other models down to about 3 to 3.5 inches, so the installation plan matters as much as the model.
Is there a lift-up or drop-down door?
No, Ella does not offer a lift-up or drop-down door; every Ella door swings either inward or outward, and the low threshold itself is the accessibility feature. The Transfer L-shape door opens the full side of the tub so a bather can slide across from a wheelchair, which serves the same purpose. The door opening widths and swing arcs for each model are published in the article linked above.
Are Ella tubs ADA certified?
There is no ADA certification program for residential bathtubs, so no walk-in tub can carry one. Ella tubs are sized to accessibility guidance, with seat heights in the 17 to 19 inch range and low step-in thresholds, so the practical approach is to compare the figures above with the needs of the bather. Our ADA and accessibility answers go into detail on what the guidance covers and how Ella models line up with it.
Can the threshold be lowered after the tub is installed?
Only by resetting the tub lower, which requires a subfloor opening for the drain body and trimming the bottom of the apron or end panel to clear the floor. That is a job for your installer rather than a homeowner adjustment, and it is far easier to plan the recess before the first installation. Read the lowering and recessed installation article linked above with your installer before deciding.
Does lowering the threshold change the warranty?
Cutting the apron or end panel voids warranty coverage on those altered panels only; the shell, frame, door and equipment keep their coverage. Because the alteration is permanent, ask your Ella dealer or the team at (800) 480-6850 before cutting so the plan protects the rest of your warranty. Have your model, serial number and a description of the intended recess ready so the team can confirm exactly what is affected.
How high is the seat?
The seat sits about 17 inches high on most models, in line with the 17 to 19 inch range used for accessible seating, and the Ultra's 17 inch seat is called out as ADA-compliant on its spec sheet. The seat is molded into the shell, so it is not adjustable. If you would prefer to sit higher, a seat pillow riser adds height without any modification to the tub.
Why does the threshold on my invoice or drawing differ from a figure I was given?
Technical drawings show the factory-preset frame height with the leveling legs at their standard setting. A figure you were given may assume a recessed drain or a different leveling-leg setting, which is why the two numbers do not always agree. If the threshold is critical for the bather, ask your Ella dealer or the team at (800) 480-6850 for the drawing for your exact model and configuration in writing before ordering.
Which family is best for a wheelchair user?
The Transfer family is the usual recommendation, because it combines some of the lowest thresholds in the line with an L-shape outward door that opens the full side of the tub for a sliding transfer. Remember that the outward L-shape door needs about 36.5 inches of floor clearance in front, which is separate from the step-in height. The Transfer tub family guide compares the five sizes so you can match the tub to the bather and the room.

For anything model-specific, open a ticket at ellasbubbles.com/support or call (800) 480-6850.

About this guide. Answers in the Ella’s Bubbles Support Center are compiled from real conversations with tub owners, our technicians’ notes and the product documentation, then reviewed by our team. Tub models and options have evolved over the years, so a detail here may differ slightly from your exact tub. If something looks different on yours, send us your serial number and a specialist will confirm it for your model.

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