I think I could start working as a consultant for Hydro Flask, being a proud owner of five different sizes (or six if you count the kids’ bottle).
Honestly, I don’t even have to test these bottles to know they’re among the best bottles on the market today. My tests confirmed it anyway, with Hydro Flask consistently scoring the highest out of all my water bottles.
If you’re reading this article, you probably already know this and are trying to find the perfect size for yourself. In this comparison, I’ll be diving into all the Hydro Flask sizes I own and explaining which one will serve you best in different scenarios.
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Water Bottle | Buy Now |
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 Best Portability Hydro Flask Trail Series 24 oz | |
 Best Versatility Hydro Flask 32 oz | |
 Best for Work Hydro Flask 40 oz | |
 Best for Stationary Settings Hydro Flask 64 oz | |
 Best for Group Activities Hydro Flask Oasis 128 oz |
Hydro Flask 24 oz.
The 24 oz. Hydro Flask is the smallest size I own, and while I don’t have the regular version, I do have a Trail Series model that I bought specifically for hiking.
It turned out to be more versatile than I initially thought. What I like most about this size is its unmatched portability. It’s the only Hydro Flask that fits in my cup holders with its 2.75-inch diameter – a huge advantage for someone like me who spends a lot of time in the car.
Another feature that enhances its portability is the fact that my Trail Series is 25% lighter than the regular Hydro Flask of the same size. On top of that, it has a very comfortable perforated strap that I can use to carry the bottle without any discomfort, even for long periods during my hikes.
But what’s beautiful about this bottle is that it’s not a one-trick pony. Although it was designed specifically for hiking, I love taking it to many other places.
Yes, it’s somewhat less durable than the regular Hydro Flask and is more prone to scratches, but if you don’t mind a few battle scars, the Trail Series is the perfect 24 oz. Hydro Flask.
Technically, you can get even smaller sizes (21 oz., 20 oz., and 18 oz.) but I wouldn’t consider them for myself. They’re simply too small, and I hate refilling them all the time.
The 24 oz. is still somewhat lacking for my hydration needs, requiring me to refill it three times to meet my daily goals. But if you prefer smaller bottles, anything below 32 oz., the 24 oz. size is a decent choice.
Hydro Flask Trail Series 24 oz |
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Best Portability |
Hydro Flask 32 oz.
The Hydro Flask size of 32 oz. is my absolute favorite among all sizes. Why can’t I live without it? In short, it offers the best balance between capacity and overall size, enhancing its portability.
These two things result in unmatched versatility that I fell in love with years ago and still going strong.
With the 32 oz. Hydro Flask, you’ll only have to refill it once to meet your daily hydration goal. This size strikes the right balance: not too small that you’re constantly refilling and not so large that it’s cumbersome.
It fits perfectly into my stationary routine, whether I’m at the gym, in class, at work, or lounging on the beach.
If you’re more of an active person, this Hydro Flask size becomes even more appealing. Investing $15 into the Flex Straw Cap allows you to sip on the go without risking splashes from the wide mouth.
I don’t hesitate to take my 32 oz. Hydro Flask for walks, short hikes, overnight trips, or sports. It’s practically glued to my hand.
The only problem that I see in this size is that it weighs around 15 ounces when empty. While it doesn’t feel super heavy, it’s certainly noticeable.
That’s why I would not take this size for extreme activities like long backpacking trips, where I usually opt for a lighter bottle.
But other than that, this Hydro Flask is the best size you can get in my experience.
Hydro Flask 32 oz |
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Best Versatility |
Hydro Flask 40 oz.
Moving on to the larger sizes, we have the 40 oz. Hydro Flask. This bottle definitely starts to feel more hefty than its smaller siblings, making it less portable compared to the 32 oz. Hydro Flask.
The main issue with this size is its weight. It clocks in at 18 ounces when empty, and if you add the heavier Flex Straw Cap, it’s even heavier. It also doesn’t help that it’s taller by a few inches, resulting in it being more cumbersome to carry around.
However, I still find myself using this size sometimes, especially in stationary settings. Some days, I prefer working remotely, and on those days, having the 40 oz. Hydro Flask on my desk is just what I need.
I don’t have to carry it anywhere, and it provides reliable insulation while holding a lot of water. It’s like having a mini water cooler right next to your laptop.
Occasionally, I also take it to the gym, and it works great in those situations too. You don’t have to keep running to the water fountain between sets, and it keeps your drink refreshingly cold.
While you could potentially take it on short hikes or walks in the park, I’d personally choose the 32 oz. size over the 40 oz. when planning to be active.
Hydro Flask 40 oz |
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Best for Work |
Hydro Flask 64 oz.
The half-gallon, or 64 oz., Hydro Flask is an interesting option. While this size may not scream “portability”, I find it to be the best 64 oz. bottle among all five bottles of this size I own, and definitely the most portable one.
Yes, it weighs 27 ounces when empty, but surprisingly, it’s on the lighter end of the spectrum for bottles with the same capacity. Compare it to options like the YETI Rambler Jug that weighs in at a whopping 65 ounces, and you start to really appreciate your Hydro Flask.
That said, it’s obvious that I wouldn’t take this bottle with me to places where I’m constantly on the move and taking it for, let’s say, a walk in the park doesn’t make much sense to me (unless it does to you).
It’s not your everyday bottle, but personally, I’ve taken it camping, to the beach, and even to the gym, and it worked fantastically in those scenarios. It can be equally useful for work, parked right there on your desk.
All in all, the 64 oz. Hydro Flask may sound intimidating at first, but it’s a lot more user-friendly than you’d think. For those who need serious hydration, it’s a fantastic choice. I really like this size.
Hydro Flask 64 oz |
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Best for Stationary Settings |
Hydro Flask 128 oz.
Finally, we’ve reached my biggest Hydro Flask, the one-gallon Oasis, which (and this may surprise you) I absolutely love.
The Oasis is aptly named because it truly serves as a literal oasis sometimes, able to hydrate lots of people in one go. This giant is perfect for those times when you need to quench not just your thirst but also that of everyone around you.
The design of the lid differs significantly from other Hydro Flasks. It features a massive lid that’s surprisingly easy to open and close, even with one hand. The cap is equally straightforward and covers a spout that allows you to pour liquids into smaller vessels without making a mess.
As with all Hydro Flasks, the Oasis also boasts a flexible handle. Despite being huge, the handle is still very comfortable to carry. Sure, it’s a bit like carrying a small child, but one that keeps your drinks nicely chilled.
That brings us to the biggest drawback: insulation performance. The Oasis’s insulation is slightly less reliable than other Hydro Flask sizes. This is because the Oasis is a massive vessel, and that sheer size influences its insulation capabilities.
However, if cold retention is what you care about, just add some ice, and it will keep your beverages cold for a full day. Yes, you might have to prep a bit more, but the payoff is worth it.
Maybe it’s just me who loves vessels this big, but the Oasis shines in social settings. If you have big family gatherings, parties, beach outings, or casual BBQ meetings with friends, investing in the Hydro Flask Oasis is actually a good idea.
No more running back and forth to the fridge to refill drinks. It’s all there, in one giant, convenient, easy-to-carry jug.
At $125, it’s not cheap, but considering how often I use it, I found it worth the price tag. The reactions alone are priceless when I pull it out at a gathering!
Hydro Flask Oasis |
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Best for Group Activities |
Conclusion
I hope this comparison cleared up any doubts you had about which size to choose. While each size has its perks in different situations, my top pick is definitely the 32 oz. Hydro Flask.
Pick the one that fits your needs, and I’m sure you’ll be happy with your purchase. Your Hydro Flask will serve you well for years to come!
Jeremiah Kowalski
Hey there! I’m Jeremiah, the guy behind WaterBottleAdvisor.com. I used to have a bad habit of guzzling sodas while working remotely, but thanks to reusable water bottles, I’ve turned my hydration game around. After testing over 50 bottles, I’m here to help you find the perfect one to make staying hydrated a joy, not a chore. When I’m not reviewing bottles, you’ll likely find me scaling steep trails around the world, trusty water bottle in hand.
