A portable cold plunge is a great idea if you’re often on the move, are renting, don’t have much space, or simply want to enjoy a cold plunge almost anywhere you imagine.

But are portable cold plunge tubs smaller? Actually, how much water does a portable cold plunge hold?

The range is quite big as it goes anywhere from 50 to 300 gallons of water, which is more than your typical full bathtub.

That’s why, in this article, we’ll break down how much water different portable cold plunge tubs and barrels hold. We’ll also share what factors affect their capacity so you know how to choose the right capacity for your needs!

How Much Water Does a Portable Cold Plunge Hold?

The amount of water a portable cold plunge can hold depends on the size, design, and intended use - but most models can hold anywhere between 50 to 300 gallons of water.

That’s a huge range, but that’s why we’ll also show you the range for different sizes of portable cold plunge tubs and barrels, and how to calculate how much water you would need for your portable cold plunge tub.

Typical portable cold plunge tub capacities are the following:

• Small (ideal for personal use) - 50 to 80 gallons

• Medium (portable tub type) - 80 to 150 gallons

• Large (barrel-style) - 150 to 300 gallons

A small portable cold plunge tub is highly convenient as it’s smaller, compact, and very mobile. It’s also very easy to fill and drain small portable cold plunge tubs.

Medium is a slightly larger tub-type cold plunge which offers more space and better submersion, but slightly reduces convenience.

Large is often a barrel-style cold plunge, which is great for full-body immersion, but it is also the size that requires the most water.

Other than the size of the portable cold plunge tub, material, shape, and even user capacity can determine how much water a portable cold plunge holds.

Factors Affecting Water Capacity

By now, you have learned that not all portable cold plunge tubs have the same water capacity. As we’ve mentioned earlier, factors that affect water capacity can include:

• Size and dimensions

• Shape and design

• Material and construction

• Intended use

• Water displacement

From our experience, the biggest factor is the size and dimension, which is why you should carefully consider length, width, and depth variations.

The next thing you should pay attention to is the shape. Designs that maximize water usage usually come with taller walls rather than wider designs. That’s why choosing between a barrel-style, rectangular, or round cold plunge tub can make a huge difference in both the compactness and water capacity it can hold.

Inflatable cold plunge tubs have flexible walls which reduces the water capacity it can hold. On the other hand, cold plunge tubs with rigid walls are ideal for everyone who’s trying to maximize their water capacity.

Elevated designs also always work better than wider footprints.

Believe it or not, there are even portable cold plunge tubs that can fit two or more people. However, these usually require much more water.

Lastly, one of the most overlooked factors is the water displacement. When someone gets in, the water level rises - which is why you can’t always fill the tub to the top and is something you have to consider when filling your tub.

How to Calculate Water Needed for Your Cold Plunge

Knowing exactly how much water you need for your portable cold plunge will make the filling process easier. As we’ve mentioned earlier, you shouldn’t overlook the water displacement when filling your tub.

While we might have to rely on math for this one, it’s the best and most accurate way to calculate how much water can your portable cold plunge hold. This is super useful, especially if you didn’t receive this information from the tub’s manufacturer.

Formula for rectangular cold plunges

Volume (gallons) = Length (ft) x Width (ft) x Depth (ft) x 7.48

Formula for round or barrel-style cold plunges

Volume (gallons) = 𝜋 x Radius2  x Depth x 7.48

Keep in mind that water displacement isn’t included in the formula and that’s something you’ll have to additionally adjust for. A rough estimate is that a 150-pound person displaces about 18 to 22 gallons of water, while a 200-pound person displaces about 25 to 30 gallons of water.

Considering the formula, here’s our estimate of the water needed for the cold plunge sizes we mentioned earlier:

• Small - 90 gallons

• Medium - 187 gallons

• Large - 337 gallons

• Round-type or Barrel-style - 147 gallons

Water Usage Considerations

When you know how much water your portable cold plunge tub needs, the next thing you need to ensure is to manage it efficiently. This includes everything from filling to maintenance, and even understanding how water usage can help you save money, resources, and most importantly - time.

We highly recommend using a high-flow hose for faster filling and if you’re using well water, use a filtration system to remove minerals.

When draining, ensure you drain in an appropriate area, and if possible, use a submersible pump for faster draining.

When it comes to water replacement, if you don’t use any filtration system, you will most likely have to change your water between 7 to 14 days, depending on usage. Investing in a chiller with filtration rather than using ice can help your water last up to a month with proper treatment.

Conclusion

If you’re looking for the best portable cold plunge for your needs, we highly recommend you look into specifications, size, and dimension, to ensure you know the right amount of space the tub will require and how much water you’ll need to fill in the tub.

Once you know the tub’s dimensions, you’ll know exactly how much water a portable cold plunge holds.

If you don’t have a portable cold plunge yet and are looking for a quality inflatable cold plunge tub, check out the Embrace Beginnings, an inflatable cold plunge barrel that holds 80 gallons of water.