Black Hydro Flask on a Shore

Hydro Flask 32 oz vs 40 oz vs 64 oz

So, you’ve made the decision – you’ll be stepping up your backpacking game by getting a quality Hydro Flask bottle. Unfortunately, doing something like this is actually a bit more difficult than one may expect. The biggest dilemma that most backpackers bump into is that of the size of their future Hydro Flask bottle.

Over the last two decades, I’ve used more than a few stainless steel bottles – including Hydro Flask ones – and in pretty much all available sizes. Therefore, I know exactly what one can gain (as well as lose) by opting for any of these sizes, including the most popular ones: 32 oz, 40 oz, and 64 oz.

In this article, I’ll be sharing this knowledge with you. Once you check out my detailed descriptions of the three different-sized Hydro Flask bottles, make sure to take a look at a few tips I’ve written down below. These should provide additional help in choosing a model of the perfect size for your needs.

Hydro Flask 32 oz – Best for Day-to-Day Use

Hydro Flask 32 oz


  • Capacity: 32 oz
  • Available Colors: 13
  • Material: Stainless steel

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First things first – the size. For a vast majority of backcountry explorers, a 40 oz stainless steel bottle feels somewhat oversized. A 24 oz bottle, on the other hand, feels way too small. The solution to this issue is quite obvious – getting a 32 oz model.

A bottle of this size is neither too big nor too small – it’s just right. This is precisely what turns the Hydro Flask 32 oz into the best choice for those looking for a stainless steel bottle for everyday use. It’s a perfect piece of drinkware to have around the house as well as for use during day hikes and shorter backcountry adventures.

In terms of materials, this model combines durable 18/8 stainless steel and BPA-free plastic. In other words, this is a very rugged bottle that is also completely safe to drink from, although that’s something to expect from a reputable manufacturer such as Hydro Flask. If the look of your hiking bottle matters to you, you’ll be pleased to know that this one can be obtained in 13 different colors.

Obviously, as an insulated stainless steel bottle, this product is also capable of keeping cold drinks cold and hot drinks hot for hours on end. Moreover, it sports a sweat-free powder coating and can be safely washed in a dishwasher. And when it comes to drawbacks, the only one I found is the (occasional) difficulty of removing the model’s lid.

All in all, a Hydro Flask bottle of this size can hold a decent amount of liquid – you won’t have to refill it too often. As I said above, it’s an ideal choice for folks looking for something that’s neither too big nor too small.


  • Holds a decent amount of liquid
  • Excellent construction & insulation
  • Available in 13 colors


  • A hard-to-remove lid

Hydro Flask 40 oz – As Versatile As It Gets

Hydro Flask 40 oz


  • Capacity: 40 oz
  • Available Colors: 4
  • Material: Stainless steel

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Almost all stainless steel bottles made by Hydro Flask sport the same construction and features. Therefore, pretty much everything I said for the 32 oz model applies to this one as well. This 40 oz variant is just as durable, functional, and practical as the bottle described above.

The only major difference is, of course, the capacity. This 40 oz version is incredibly popular for a good reason – it is as versatile as it gets. In other words, it has everything that an outdoor enthusiast, college student, office worker, or any person who drinks water frequently may need.

Years ago, I considered 40 oz stainless steel bottles to be kind of…awkward. I thought they were too big to be used in a comfortable way, as well as too bulky to be carried around without much effort. Only later have I realized that these flasks aren’t really significantly taller than the 32 oz bottles – they sport a wider diameter and allow one to carry more liquid while still being fairly convenient to use.

Just like the 32 oz version, Hydro Flask 40 oz also sports a powder finish. Here, this coating is even more important due to the bottle’s larger size. The model’s surface is rough and dry, making it easy to drink from it with just one hand.

The manufacturer’s proprietary TempShield insulation, on the other hand, effortlessly maintains the temperature of one’s drink. Hot drinks stay piping hot and cold drinks stay icy cold, and that’s just what you need during your wintertime/summertime trekking adventures. The model is also dishwasher-safe and comes accompanied by a lifetime warranty.

Is this the right Hydro Flask bottle for your needs? Even though I said that a 32 oz model feels just right in the hands, some folks will still need a bit more water in order to stay hydrated during their activities. If you count yourself among them, this bottle is perfect for you.


  • Versatile – ideal for all sorts of activities
  • Easy drinking & cleaning due to a wide mouth
  • Lifetime warranty


  • To avoid leaks, the cap needs to be screwed really tight

Hydro Flask 64 oz – For Families and Trade People

Hydro Flask 60 oz bottle


  • Capacity: 64 oz
  • Available Colors: 13
  • Material: Stainless steel

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The last Hydro Flask bottle I’ll be taking a look at is also the largest one. As a 64-ounce model, it has enough capacity to store a lot of water, tea, coffee, or any other beverage you like. This turns it into a phenomenal choice for several different categories of people.

First of all, Hydro Flask 64 oz is a great option for groups of hikers/campers/hunters. For example, if you often go on hiking adventures with the members of your family, this particular stainless steel bottle will allow you to bring enough water to keep everybody well-hydrated throughout the day.

However, in my opinion, this Hydro Flask bottle is an absolutely ideal choice for trade people and laborers. If you’re someone who works a lot and really needs a few sips of cold water every now and then, this high-capacity bottle can come in very handy. I also think that it’s a pretty good option for truck drivers and other folks who spend whole days on the road.

Apart from capacity, everything about this model is identical to the two Hydro Flask bottles described above. Obviously, the TempShield insulation is its most important feature – it’s the thing that maintains the temperature of the drinks and makes the tea you filled the bottle with still hot even in the afternoon.

There is also a slip-free powder coating, a wide mouth, as well as Hydro Flask’s famous lifetime warranty. Unlike the 40 oz bottle described above, this particular model is available in many more chic colors – 13 of them, to be more precise. It also costs more, but the higher price is definitely justified by the higher capacity.

I would recommend going with a Hydro Flask bottle of this size if you often hike/camp with a family or if you’re a truck driver or a laborer who needs a lot of water during his workdays. It’s an incredibly well-made stainless steel bottle with enough space for plenty of water, tea, coffee, or any other drink you like. If you are considering going with another brand, check out our post on the best Hydro Flask alternatives.


  • Great for families and laborers
  • Slip-free coating & convenient handle
  • Excellent insulation


  • Pricey

How to Choose the Correct Size of Your Hydro Flask Bottle

Hydro Flask bottle on leaves

Bigger is Often Better

As you may know, Hydro Flask bottles are pricey, and the bigger they are, the more they cost. But if you really can’t decide whether to go with a bigger or a smaller model, go with the former option. After all, finding yourself far away from water sources with only a couple of sips left in your bottle can be quite dangerous and often life-threatening.

Although it’s true that larger stainless steel bottles are more difficult to carry and handle – and they also can’t be used with car cup holders – they provide you with more water, as simple as that may sound. Having an abundance instead of not enough water is surely a better scenario to find yourself in.  But,

What Do You Need the Bottle For?

Large Hydro Flask on a tree stump

A Hydro Flask bottle of a certain size will work wonderfully for some activities, but not for others. And that’s precisely why you need to think long and hard about what you need a product of this type for before you actually purchase one.

If you need a bottle for school, hiking, office, or some sport, make sure to get the best size for that particular activity. Those who need a bottle that they’re going to use at the office, for example, are best off with a 32 oz model. Such a bottle can hold enough water to keep one hydrated until the end of their shift.

Obviously, none of the three sizes we talked about in this article are suitable for kids. If you’re shopping for a Hydro Flask bottle for your child, your best bet is to go with a 12 oz or 18 oz model. These bottles are large enough to hold a decent amount of water while still easily fitting inside smaller backpacks.

Trust Your Gut

As simple as this may sound, following your instinct is often the best course of action when it comes to choosing a stainless steel bottle of the right size for your needs. Is your subconscious mind trying to tell you something? If so, make sure to listen to it – that’s rarely a bad decision.

Over the last couple of decades of backcountry exploration, I’ve learned two things – trekking gear can be very expensive, and trusting your instinct while shopping for it is a sure way to end up with stuff that you won’t want to throw away after only a couple of days of use. Going against my instincts, on the other hand, usually leaves me with buyer’s remorse.

To put it simply, if your subconscious mind is telling you that you should go with a 40 oz Hydro Flask bottle – or with a model of any other size, for that matter – then that’s what you should do, without hesitation. It’s simple but it works like a charm!

The Takeaway

Closeup of a Hydro Flask

As you may have expected, there’s no simple answer to the question of “which size of a Hydro Flask bottle is the best”. What works for one person may not work for another and vice-versa.

In my opinion, the 40 oz version is unmatched in terms of versatility, but if you only go on short day hikes, a 32 oz bottle will probably be a better choice for you.

In the same manner, the 64 oz variant stands as the best option for trade people and families going on multi-day adventurers in the backcountry.

If you are considering going with a budget-friendly alternative, check out our Hydro Flask vs Klean Kanteen bottle comparison and our Hydro Flask vs EcoVessel bottle comparison.

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