How big is a standard bathtub, and how do you measure yours?

A standard bathtub alcove is commonly 60 inches long, and that length, rather than the size of the old tub itself, is the number that decides what will fit in its place. To measure yours, record the finished length between the walls, the width from the back wall to the front edge of the alcove, and the height from the floor to the bottom of any window sill, then compare those figures with the actual size printed on the spec sheet of the tub you are considering. Will a Walk-In Tub Fit Where My Old Tub or Shower Stall Is Now? runs the full fit check, and this page concentrates on the measuring itself and on what the numbers mean once you have them.

Why You Measure the Opening, Not the Old Tub

Ella walk-in tubs are built for a standard three-wall alcove and can also stand free against one or two walls, so the finished space is what matters. The tub you are removing may be shorter or narrower than the opening it sits in, and it may sit under a window that limits the usable height. Start from the walls and the floor, never from the rim of the old tub.

The second reason is that the size in a model name is a nominal figure. The Ella Petite is marketed as a 28 inch tub, but its actual size is 27.5 inches wide by 52 inches long by 35 inches tall, and the Ella Elite is 30 inches wide by 52 inches long by 35 inches tall. Always compare your measurements with the actual dimensions on the spec sheet, not with the name on the brochure.

A walk-in tub also does not have to fill the whole alcove on its own. Ella tubs shorter than 60 inches include an extension panel that closes the gap between the tub and the end wall, so a 52 inch model goes into a 60 inch alcove and still looks finished. That is why the compact 52 inch models are the usual starting point when a shower stall, which is often shorter and narrower than a tub alcove, is being replaced.

How to Measure Your Bathtub Space, Step by Step

1. Measure the length between the finished walls at the two ends of the alcove. This is the figure to compare with the tub's length.
2. Measure the width from the back wall to the front edge of the alcove. This is the figure to compare with the tub's width.
3. Measure the height from the floor to the bottom of any window sill, and compare it with the tub's height.
4. Measure the doorways and hallways the tub must pass through on delivery day. A crated tub is larger than the tub itself. The Escape, for example, ships in a crate measuring 40 by 76 by 49 inches at 398 pounds.
5. Note which side the existing drain is on. On every Ella walk-in tub the door and the drains are on opposite sides. A right-side door tub has its drains on the left, and a left-side door tub has its drains on the right, with sides taken as you face the tub.
6. If you are replacing a shower stall, measure the wall-to-wall distance after the seat, glass enclosure and curb are removed, because those parts are not part of the finished opening.

Keep those numbers together with the drain side. They are what your Ella dealer or the team at (800) 480-6850 will ask for, and they are what your plumber needs in order to confirm whether the existing drain and supply lines have to move to meet the tub. Your electrician confirms the electrical supply the tub needs at the same visit.

How Walk-In Tub Sizes Compare with a Standard Alcove

What the differences mean: the 52 inch models fit almost any opening that held a standard bathtub and leave the extension panel to finish the gap, while the Ultimate is the model to look at if you want the tub itself to span a 60 inch alcove. The Big4One and the ShaK are longer than a standard alcove, so they need an opening that measures at least 66 or 72 inches between finished walls, and the two-seat Escape needs the same 72 inches plus clearance for a 40 inch tall shell under any window. Standard-size Ella models hold 65 to 107 gallons unoccupied, so the larger the tub you choose, the more hot water your heater has to supply for each bath.

Measuring for Soaking Depth, Not Just the Footprint

The first video on this page explains that the overall soaking depth of a walk-in tub is determined by three factors: the interior length of the tub, the length of the seat, and the depth from the top of the seat to the center of the overflow drains. A bather's own size then determines the depth they actually get, so keep those three factors in mind as you choose. The exterior measurements tell you whether the tub fits the room, and the interior ones tell you whether it fits the bather. For a broad bather or a couple, Can two people fit in a walk-in bathtub, and how big is it? compares seat widths across the two-seat family, and the Escape's 27 inch and 29 inch seats are the widest of them, as What is the Ella Escape 36x72 two-seat walk-in tub like? details.

Door Swing and Floor Space in Front of the Tub

One measurement a standard bathtub never needed is the clear floor space in front of the tub. The Tub4Two and the Big4Two use the outward-swinging U-shape door, which needs clear floor space in front of the tub to open, while the Escape and the Companion use an inward-swing stainless steel door that lifts out for cleaning. When the room in front of the tub is tight, an inward-swing model is the one to look at. What is the biggest walk-in bathtub size you can buy? explains what the largest models demand from a bathroom, including that clear floor space.

Watch: How to Measure the Soaking Depth of Your Walk-In Tub | Ella’s Bubbles with chapters and a full transcript.

Related Guides

• How Deep Is the Water Really in a Walk-In Tub?
• Interior Length, Seat-to-Overflow and Seat-to-Footwell by Model: The Soaking Depth Table
• What Is Nominal Size vs Actual Size on a Walk-In Tub?

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