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Interior Length, Seat-to-Overflow and Seat-to-Footwell by Model: The Soaking Depth Table

Updated September 2026

▶Glossary10
  1. How Soaking Depth Is Measured
  2. Reading the Columns
  3. Stainless Steel Inward-Door Family
  4. U-Shape Outward-Door Family
  5. L-Shape Wheelchair Transfer Family
  6. Two-Seat Family
  7. Models Not on the Chart: Standard Family and Ultra
  8. Putting It Together
  9. Related Guides
  10. Common Questions

Soaking depth in a walk-in tub is not one number. It comes from three measurements working together: the interior length of the tub, the length of the seat, and the distance from the top of the seat to the center of the overflow. Ella's Bubbles publishes those measurements for every model on its comparison chart, and the tables below collect the interior dimensions and soaking depth by model so you can compare families side by side. Where a marketing video rounds a figure, the spec sheet and this chart govern.

How Soaking Depth Is Measured

How to Measure the Soaking Depth

Watch: How to Measure the Soaking Depth of Your Walk-In Tub with a full transcript.

The clip states the rule that appears in every Ella product video. The overall soaking depth of an Ella walk-in tub is determined by three factors: one, the interior length of the tub; two, the length of the seat; and three, the depth from the top of the seat to the center of the overflow drains. A bather's own size then decides the actual result, so keep the three factors in mind as you choose a tub. For the companion guide on measuring your own hips, shoulders and seated length, see seat sizes and soaking depth.

Overhead view of a woman seated in the Ella Petite walk-in tub with the 19 inch seat width and shoulder width marked
Seat width, interior length and seat-to-overflow height together set how deep you sit in the water.

Reading the Columns

  • Interior length is the usable length inside the shell from the backrest to the far wall; a longer interior lets your legs extend.
  • Seat length is how far the seat projects forward; a longer seat supports more thigh but takes up interior length.
  • Seat to overflow top is how deep the water can rise above the seat. Water cannot be filled above the overflow, so this is the practical soaking depth for the torso.
  • Seat to footwell is the drop from the seat surface to the floor, which sets how far your feet sit below the seat.

Stainless Steel Inward-Door Family

ModelNominal sizeSeat widthSeat lengthInterior lengthSeat to overflowSeat to footwellFootwell
Elite52 by 30 in.22 in.12 1/4 in.45 in.15 1/2 in.15 in.17 W by 20 1/2 L
Petite52 by 28 in.19 in.13 in.45 1/2 in.15 3/8 in.15 in.17 W by 21 L
Royal52 by 32 in.23 in.12 1/4 in.45 1/4 in.15 1/2 in.15 in.19 1/2 W by 20 L
Deluxe55 by 30 in.21 in.15 1/2 in.47 1/2 in.19 in.15 in.17 W by 19 L
Ultimate60 by 30 in.21 in.16 in.51 1/4 in.18 1/2 in.15 in.19 W by 21 L

U-Shape Outward-Door Family

ModelNominal sizeSeat widthSeat lengthInterior lengthSeat to overflowSeat to footwellFootwell
Capri52 by 30 in.20 in.14 1/2 in.43 3/4 in.17 1/4 in.17 in.17 W by 15 L
Monaco52 by 32 in.23 in.13 3/4 in.44 1/2 in.16 5/8 in.17 in.19 W by 18 L
Lounger60 by 27 in.20 in.16 in.50 1/2 in.17 in.17 in.16 W by 20 L
Big4One66 by 33 in.24 in.21 1/4 in.58 in.22 in.17 in.20 W by 17 L
Shak72 by 36 in.28 in.26 3/4 in.66 1/4 in.16 1/2 in.17 in.22 1/2 W by 14 1/2 L
Front Entry40 by 32 in.25 in.13 1/2 in.34 3/4 in.18 1/4 in.16 in.19 W by 13 L
Mobile45 by 26 in.20 in.14 in.38 7/8 in.18 1/2 in.15 in.18 W by 14 1/4 L

L-Shape Wheelchair Transfer Family

ModelNominal sizeSeat widthSeat lengthInterior lengthSeat to overflowSeat to footwellFootwell
Transfer2652 by 26 in.19 in.16 3/4 in.43 5/8 in.17 1/2 in.17 in.15 1/2 W by 17 1/2 L
Transfer3052 by 30 in.22 in.15 3/4 in.43 3/4 in.18 1/2 in.17 in.18 W by 17 L
Transfer3252 by 32 in.24 in.16 7/8 in.43 3/4 in.19 3/4 in.17 in.19 1/2 W by 17 1/2 L
Transfer6060 by 30 in.22 in.18 1/2 in.50 3/4 in.19 5/8 in.17 in.17 W by 19 L
TransferXXL55 by 36 in.29 in.17 3/4 in.48 1/8 in.17 3/4 in.17 in.23 W by 18 L

Two-Seat Family

ModelNominal sizeSeat widthsSeat lengthsInterior lengthSeat to overflowSeat to footwell
Big4Two80 by 36 in.22 and 24 in.19 1/2 and 20 in.37 3/8 in. (chart)19 1/4 in.17 in.
Escape72 by 36 in.27 and 29 in.16 1/2 and 17 in.63 7/8 in.18 1/2 in.15 in.
Tub4Two60 by 31 in.20 and 22 in.12 1/8 and 12 1/8 in.56 3/4 in.15 3/4 in.17 in.
Companion60 by 32 in.23 and 25 in.11 and 12 1/2 in.54 5/8 in.18 7/8 in.17 in.

Seat widths follow the current spec sheets, which print 23 inches for the Royal and, on the Monaco drawing, 23 inches at the seat. On two-seat tubs the interior length is shared between the two facing seats, so each bather's leg room is roughly the interior length less the other seat's length. The chart's 37 3/8 inch entry for the Big4Two appears to describe the space in front of one seat rather than the full 80 inch tub; confirm with the drawings in the Big4Two specifications before planning around it. Our two-seat tub comparison looks at how the four models share their space.

Overhead view of the Ella ShaK 36 by 72 inch walk-in tub showing its 28 inch seat, long interior and contoured footwell
The ShaK has the longest interior in the line at 66 1/4 inches, with a 26 3/4 inch seat.

Models Not on the Chart: Standard Family and Ultra

These four are not on the comparison chart, so their figures come from product videos and spec sheets: Standard, 43 inch interior, 22 by 18 inch seat, 15 inch soaking depth; Flow, 39 3/8 inch inner length on the spec sheet, 20 by 13 inch seat; Zen, 20 by 15 inch seat; Ultra, 42 inch interior, 19 inch seat length, 17.5 inch soaking depth. Ask the team for the Zen interior lengths in writing if you need them.

The Ella Ultra: Walk-In Tub With Ultra-Luxury Features
Chapters in this video
  1. 0:00 Introducing The Ella Ultra Tub The Ella Ultra walk-in tub is introduced, highlighting its durable acrylic, low-threshold entry, and slip-resistant floor.
  2. 0:31 Spacious Interior And ADA Features The unique design enhances interior space, providing ample room for bathing comfort with ADA-compliant seat height and length.
  3. 1:12 Innovative Jetting And Foot Massage The tub features three-speed air massage with auto purge, luxurious hydromassage with an inline heater, and an optional independent foot massage.
  4. 2:06 Fast Fill, Dual Drain, And Controls The Ultra includes a five-piece fast-fill faucet, Ella's exclusive dual drain technology, and a choice of digital or easy-touch controls.
  5. 2:29 Luxury Features And Accessories Optional features like LED chromatherapy, a heated seat and backrest, a four-fold glass screen, and a rain head shower column are available.
  6. 3:00 Magnetic Access Panels The tub is equipped with magnetic access panels for convenient servicing and maintenance.

The Ultra video states the 42 inch interior, 24 inch shoulder width, 17 inch seat height, 19 inch seat length and 17.5 inch soaking depth, and shows the reversible extension panel. Watch: The Ella Ultra: Walk-In Tub With Ultra-Luxury Features with chapters and a full transcript.

Top-down view of the Ella Deluxe 30 by 55 inch walk-in tub showing the 21 inch seat, hydro jets, grab bar and open inward door
The Deluxe: 47 1/2 inch interior, 19 inch seat-to-overflow.

Putting It Together

A tall bather wants the longest interior with a moderate seat length, which points to the Ultimate, Lounger, Transfer60, Big4One or Shak. A bather who wants the deepest water over the torso should look at seat-to-overflow: the Big4One at 22 inches, the Transfer32 at 19 3/4 inches, the Transfer60 at 19 5/8 inches and the Deluxe at 19 inches lead the single-seat families. A petite bather may prefer a shorter interior so the feet reach the footwell wall, which is where the Petite, Transfer26 and Front Entry sit. Nominal sizes on this chart are marketing roundings; the actual size on each spec sheet is the figure to measure the room against, and the spec sheets and drawings by model article shows where to download them. The backrest recline angles article adds the other comfort factor, how far each seat leans back.

Common Questions

What is the interior length of my model?
To find the interior length of your Ella's Bubbles walk-in tub, locate your specific model in the tables provided on this page. The interior length is listed in the 'Interior length' column, which corresponds to the data from the ellasbubbles.com comparison chart. For models like the Standard family and the Ultra, their interior lengths are detailed in a separate section on this page, with the Ultra having a 42-inch interior length.
How deep can I soak in each model?
Use the seat-to-overflow column. The water stops at the overflow, so that figure is the maximum depth above the seat. Across the mid-size models it runs roughly 15 to 18 inches, and the deepest single-seat soak is the Big4One at 22 inches.
Will the water cover my shoulders?
It depends on your seated torso length compared with the seat-to-overflow figure. Sit in a chair and measure from the seat to your shoulder; if that number is well above the tub's seat-to-overflow, the water will sit lower on your chest. A taller bather sits higher in the same water than a shorter one.
What is seat-to-overflow versus seat-to-footwell?
Seat-to-overflow measures up from the seat to the water line; seat-to-footwell measures down from the seat to the floor. Seat-to-footwell is 15 to 17 inches on every model, a chair-like height that makes standing up easier.
How is soaking depth measured?
By combining interior length, seat length and seat-to-overflow, then allowing for the bather's own size. There is no single published calculator; the three numbers in the table are what you compare against your own measurements.
Which tub is best for a tall bather?
The ShaK (66 1/4 inch interior) and Big4One (58 inch interior) are built for bathers around 6 feet and taller, and both have long seats. The Ultimate, Lounger and Transfer60 give around 50 inches of interior length in a narrower footprint. See bariatric and large-bather options for the full picture.
Which tub suits a shorter bather?
A shorter interior lets the feet reach the footwell wall for support, so the Petite, Transfer26, Front Entry and Mobile are comfortable choices. The two extra-large tubs have very long seats that can feel awkward for an average or shorter person.
Is the seat height adjustable?
No, the seat height in an Ella's Bubbles walk-in tub is not adjustable because the seat is molded directly into the tub's shell. If you wish to sit higher in the tub, you can use a seat pillow riser, which will add a few inches to your seated height. However, adding a seat pillow riser will also reduce the practical soaking depth by the same amount.

For anything specific to your model or your order, 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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