How Many Gallons of Water Does a Walk-In Tub Hold?


While alcove and free-standing tubs are the most common types of bathtubs you’ll find in typical homes, walk-in tubs can provide an alternative for people seeking greater accessibility and comfort in their bathing experience.

Larger than a normal tub, walk-in tubs often come equipped with safety features, such as a door and seat, and may even require an upgraded water heater to sufficiently heat the increased amount of water in the tub.

Key Takeaways:

  • The typical walk-in tub holds 40 to 80 gallons of water, nearly twice as much as a standard bathtub, which holds 25 to 45 gallons.
  • Walk-in tubs can run from 38 to 84 inches long but are typically about 52 inches long — smaller than standard bathtubs that run 60 inches in length.
  • Larger walk-in tubs may require you to upgrade your water heater if the tub’s capacity exceeds your current one.
  • While filling and draining times vary based on water pressure, a typical walk-in tub can take about six to 15 minutes to fully drain, and the door must remain closed as the water drains.

General Walk-In-Tub Statistics

While walk-in tubs may be a costlier option than typical bathtubs equipped in most homes, the U.S. market for these upgraded tubs was valued at $757 million in 2022 and is expected to reach nearly $942 million by 2028.

The growing market for walk-in tubs comes as a rising aging population and higher rates of obesity drive greater interest in more accessible tubs.

The decision to purchase a walk-in tub comes with various pros and cons, such as greater accessibility and relaxation, as well as longer fill and drain times coupled with higher costs.

Walk-In Tub Capacity

When purchasing a walk-in tub, it’s important to consider your home’s water heater capacity. The average capacity of a walk-in tub is 40 to 80 gallons, while a regular bathtub can only hold between 25 and 45 gallons. 

If a water heater’s capacity is lower than that of a tub, there may not be enough hot water to fill the tub. Generally, you’ll need a water heater with a capacity of at least two-thirds the size of the walk-in tub. Manufacturers may also provide information about recommended water heater capacity based on a tub’s size.

Depending on a home’s water pressure, fixtures, plumbing and the tub itself, most walk-in tubs take up to 10 minutes to fill and up to 15 minutes to drain.

How Does a Walk-In-Tub Work?

Walk-in bathtubs are built with a low step-in (between 2 to 8 inches) that allows for easier tub entry and exit by simply stepping directly in or out of the tub instead of crossing over the tub’s side by lifting one leg after another.

Walk-in bathtubs are equipped with sealed doors (to prevent leaks) that can open either inward or outward and from the left or the right. Tubs also usually come with a textured surface to prevent slipping, a heat-producing seat and a hand-held shower.

To use a walk-in tub, simply open the door, step inside and close the door before filling the tub. After bathing, allow the tub to fully drain before opening the door and exiting.

Tub size, a home’s water pressure and the age and quality of the plumbing can all affect the time it takes to fill and drain a tub.

  • Time to fill up a standard walk-in tub: six to eight minutes
  • Time to drain water out of most walk-in tubs: six to 15 minutes
  • Time to drain water out of fast-draining models: two to four minutes

Types of Walk-In Tubs

Walk-in tubs are typically about 52 inches long. However, the size of walk-in tubs can vary significantly, from as small as 38 inches long for a “cub model” or “front loader,” which have limited accessibility, to as long as 84 inches for large walk-in tub and shower combinations.2

Common varieties of walk-in tubs include the following:


How big is a walk-in tub?

A walk-in tub is usually about 52 inches long but can vary from 38 inches to 84 inches in length. Typical walk-in tubs can hold anywhere from 40 to 80 gallons, significantly more than standard tubs that hold 25 to 45 gallons of water.

Do I need a bigger water heater for my walk-in tub?

Generally, your water heater capacity should be greater than that of the tub to ensure there is enough hot water to fill the tub. Manufacturers generally provide information about recommended water heater capacity based on the size of the tub.

How long does a walk-in tub take to drain?

A walk-in tub can take more than six minutes and up to 15 minutes to drain, though fast-draining models offer draining times as short as two minutes.


How Many Gallons of Water Are In A Walk-In Tub?” Expo Home Improvement. Evaluated May 10, 2024.

Lee, S. “Walk-In Tub Sizes.” Modernize Home Services. Evaluated May 10, 2024.

How much water does a walk-in tub hold?” TopTier Kitchens. Evaluated May 10, 2024.

The Challenges of a Walk-in Tub (And How to Get Around Them).” American Tubs. Evaluated May 10, 2024.

US Walk-in Bathtubs Market - Focused Insights 2023-2028.” Global Information; Arizton Advisory & Intelligence. Evaluated May 10, 2024.

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