When hiking and backpacking, we tend to bring only the bare minimum.
But what’s the bare minimum when it comes to water?
When I first started hiking, my biggest fear was running out of water mid-trek. But bringing 10 gallons of water wasn’t an option, either.
So, I did some in-depth research on how to calculate how much water to bring hiking while keeping some different factors in mind.
A general rule of thumb is to bring 40 oz of water for every 2 hours of hiking.
In this article, I’ll show you factors you should take into consideration, as well as other things you should know about staying properly hydrated while on the trail.
Let’s dive in!
Calculating How Much Water To Bring Hiking
|Recommended Water Amount
|Approx. # of Water Bottles
|16–32 oz (0.5–1 L)
|32–48 oz (1–1.5 L)
|48–64 oz (1.5–2 L)
|32–48 oz (1–1.5 L)
|48–64 oz (1.5–2 L)
|64–96 oz (2–3 L)
|48–64 oz (1.5–2 L)
|64–96 oz (2– 3 L)
|96–128 oz (3–4 L)
|64–96 oz (2–3 L)
|96–128 oz (3–4 L)
|128+ oz (4+ L)
Please Note: The number of water bottles provided in the table is an approximation based on standard 16.9 oz (500 ml) bottles.
Depending on the water bottle size you have available, you may need to adjust the number of bottles accordingly.
Additionally, consider factors like the weather and individual hydration needs when deciding how much water to carry on your hike.
But this is just a basic guideline that should be adjusted based on other factors.
Factors To Consider When Figuring How Much Water To Bring Hiking
There are several things you need to keep in mind when calculating how much water to bring hiking. That’s why it is super important to do your research before embarking on a hike.
Here’s what you need to know about how different factors affect the total amount of water you should bring.
One of the things that affect the amount of water needed for your hike is the climate.
It doesn’t take a scientist to know we lose way more body fluids on a hot or humid day. We can lose as much as 3.6 gallons of sweat per day in hot weather.
This amount depends on both our metabolic rate and how accustomed we are to a certain temperature. In other words, a Coloradan hiker probably won’t sweat as much as an Alaskan when hiking through the Grand Canyon.
On really hot hiking days, you might need to drink up to 40 oz per hour. On the other hand, that same amount could last you 2+ hours during a colder time of the year.
Type Of Terrain
The type of terrain also affects how much water your body will be losing while on the trail.
For instance, walking on sand or snow can be quite exhausting.
The harder the terrain makes you work, the more fluids you’ll lose in the process.
If you’re going on a more strenuous hike, consider bringing 20 oz of extra water for every hour of the hike.
Here’s one thing you may not know: Our bodies lose water twice as fast at high altitude as they do at sea level.
Fun fact: The connection between altitude and hydration was discovered in 1968, when the Olympics were held in Mexico at an altitude of 7,400 feet.
This phenomenon happens for two reasons:
The first reason is that our breathing rate increases in order to compensate for lower oxygen intake. The faster we breathe, the quicker water evaporates through our skin.
The second reason lies in the dry air at high altitudes. The higher you go, the less oxygen there is. Therefore, your body begins to take faster, shallower breaths to compensate for the oxygen loss, causing you to lose more fluids.
So, depending on the altitude you’re climbing at, you might need to bring up to 50 additional ounces of water per day.
Duration Of The Hike
Once you do the math and figure out how much water you might need for an hour of hiking, multiply that by the number of hours you anticipate being on the hike.
Of course, figuring out the duration is not an easy task, especially if you have never done that trail before.
But what you can do is get a rough estimate, based on your physical condition and the average duration of other hikers.
Plus, some hiking apps will present user-based estimates for how long it may take the average hiker to complete a trail based on their own experiences.
This will always vary, of course, but it should give you a general idea of how long you can expect to be out on the trail.
Of course, it’s always better to bring more than less, as you can’t predict whether something will prolong your trip.
Intensity & Difficulty Level
Physical exertion is another factor to take into consideration when calculating how much water you need to bring.
The harder you work, the more you’ll sweat. As a result, your body needs more fluid intake to keep the levels balanced.
The steepness of the trail can also contribute to water need. This is especially important if you’re going uphill, as you’re producing way more energy to fight gravity and move upwards.
The second is the weight of your pack. Obviously, a backpack is an essential hiking item, as it helps you carry everything you need.
However, the heavier it is, the more difficult it gets for you to move around while carrying it.
Finally, we can’t forget about personal factors.
On one side of the spectrum, we have those people who seamlessly chug down a whole bottle of water. And on the other side, there are those who only take a sip and are ready to continue.
While neither extreme is great, both types of people are simply doing what their bodies tell them to do. And in most cases, that’s okay.
So, keep in mind the recommended hourly water intake, but don’t feel obliged to drink that amount religiously.
After all, hiking is supposed to be fun, and it won’t be if you’re feeling too thirsty or too full from drinking water.
Another personal factor to consider is your physical wellness. Some people are more accustomed to hiking long trails, so their bodies are used to conserving water and distributing it.
If you are just getting into hiking, you may want to lean on the side of having too much water than not enough. Introducing your body to new forms of physical exertion can tire you out in ways you won’t anticipate!
Water Bottles Vs. Hydration Bladders
Considering the hydration pack was invented for hiking, you might think that the choice between the two is pretty clear, but there are pros and cons of each.
Hydration bladders are easy to use: just slip them into your backpack and take a sip whenever you want – hands-free!
Occasional sips are ideal for staying hydrated through the entire hike.
With a water bottle, you need to remove your backpack to take it out of its pocket. Sometimes, doing this is too much of a hassle, and we end up skipping on drinking until we’re really thirsty.
And that’s not healthy.
But a hydration pack has its downsides, too. For example, they are hard to refill.
This is especially true if it’s stored in an internal sleeve. In that case, you need to empty out half of your backpack and disconnect the tube before you can reach it.
Another downside is maintenance. The tube is especially hard to clean and dry. But if you fail to do so, it can grow mold in just a few days. Because of this, you can never afford to be too lazy to clean it right after use.
Water bottles, on the other hand, are simple to clean.
If you can keep up with regular maintenance, I do recommend a water bladder. If it sounds like too much trouble, then a water bottle is the better option for you.
What Happens If You Don’t Stay Hydrated
You might think that skipping on regular sips during a hike is no big deal, but the science tells otherwise.
In fact, research shows that being dehydrated by as little as 1% can affect your mood, attention span, memory, and physical well-being.
By definition, dehydration occurs when the amount of body fluids we lose is larger than the amount we take in. That’s why we have to make sure we’re taking in more when we’re losing more – like on a hike.
If you’re feeling thirsty, you’re already dehydrated. And if you don’t drink some water, you’ll soon start to show other dehydration symptoms.
Aside from thirstiness, other early symptoms include loss of energy and dry mouth. These quickly go away as we take a much-needed sip of fluids.
But what if you continue to ignore your body’s messages to have a drink?
Well, eventually more severe symptoms will appear, such as headaches, cramps, nausea, and dizziness.
These symptoms are the last thing you need on the trail. That’s why you should never ignore the signals your body is sending you.
Is There Such A Thing As Too Much Water?
Considering that water contains zero calories, drinking too much can’t hurt, right? Wrong!
Our kidneys are in charge of getting rid of excess water from our system. But they can only excrete around 33 oz of liquid per hour.
So if you drink too much water, it will end up diluting the sodium in your blood. This is called hyponatremia.
The symptoms are similar to dehydration, which might confuse you into drinking even more water.
Overhydration is just as dangerous. In extreme cases, it can even cause death.
Don’t worry, though. There’s no need to be concerned about that, as long as you’re drinking sensibly.
In other words, don’t drink more than your kidneys can excrete each hour.
But it’s not just drinking too much water that can cause hyponatremia. We lose salt as we sweat, too, and that can also put you in danger.
Luckily, there are ways you can balance your sodium levels while hiking. For example, try an electrolyte-rich drink or salty snack.
Purifying Water From A Natural Water Source
Having a natural water source on your trail can save you some storage space.
But that doesn’t mean you can just grab a sip from that beautiful, sparkling pond of water over there. There are tons of pathogens swimming around in there just waiting to wreak havoc in a delicate stomach like yours.
A million microorganisms living in natural water sources can cause waterborne diseases like giardia, typhoid fever, cholera, and even hepatitis A.
But if you purify it, you can turn water from any source into safe drinking water.
Water filter straws are the most popular choice among hikers. They have microfilters that only let water molecules come through, while keeping all the pathogens on the other side.
You need to wait for around 15 minutes before you can drink it, which can be annoying.
But in case you can’t get your hands on a water filter straw, this is a good alternative.
5 Bonus Tips For Staying Hydrated On The Trail
Here are a few other things you can do to stay on track with your hydration while hiking:
Hydrate Before You Hit The Trail
Drink 12–16 oz of water before you even start your hike.
That way, you just need to maintain your hydration levels by continuously sipping fluids at regular intervals throughout the entire trail.
Set A Timer
When we’re out enjoying the wild, we might forget to take a sip every now and then.
To avoid that, set a reminder every 20 minutes.
Stock Up On Electrolytes
As we’ve established already, drinking too much water will cause your sodium levels to drop.
But what can you do if you’re thirsty as hell?
A good solution in this type of situation is to pop an electrolyte gel or a tablet. They will make up for all the salts you’ve lost through sweating and quenching your thirst with water.
Dress For The Weather
Wear breathable, moisture-wicking clothing that won’t make you sweat as much.
That way, you don’t have to bring 10 gallons of water just to replenish what you’ve lost through perspiration.
Avoid The Midday Sun
Dehydration is no fun, and neither is heat stroke.
To avoid these issues, start your hike early in the morning and find a shaded place to rest during the hottest hours of the day.
Can I Substitute Water With Other Beverages Or Fluids While Hiking?
While water is the best choice, you can substitute it with other drinks. Sports drinks are a good alternative, as they help you replenish electrolytes lost from sweating.
Avoid drinking coffee, tea, or soda, as caffeine in them can be dehydrating.
Are There Any Alternative Methods For Carrying Water Apart From Hydration Bladders Or Water Bottles?
If you’re not fully satisfied with either, consider getting a hybrid solution! Today, you can easily find a collapsible bladder or a water bottle with a tube on the market.
Can I Rely On Natural Sources Of Water Entirely & Avoid Carrying Water With Me?
Yes, but only if you have some kind of water purification system available.
Filter straws allow you to drink directly from the source, while purification tablets can clean your already collected water.
How Can I Gauge My Hydration Needs If I’m Hiking In A High-Altitude Environment?
At high-altitude settings, expect to drink water more often than you’re typically used to.
Since your body is losing fluid twice as fast, you should also double your water intake each hour.
Are There Any Creative Ways To Stay Hydrated On Longer Hikes Without Carrying Excessive Amounts Of Water?
If there’s a body of water available nearby, you can consider cleansing that water for consumption.
There are a few ways to do that, from purification tablets and filter straws to boiling or distilling water.
Can You Refill Water Bottles Or A Hydration Pack On A Hike?
While water bottles are pretty straightforward to refill, that’s not the case with a hydration pack.
First, you need to reach it inside the backpack, which often means removing some of the content. Then, you need to disconnect the tube to get the hydration pack out.
Once the pack is refilled, you need to do the whole process in the inverted order. The whole thing is rather time-consuming compared to refilling a water bottle.
To Sum Things Up
Staying hydrated while doing an intense physical activity such as hiking or backpacking is not simple.
There are several factors to consider when it comes to working out how much water you’ll need, and that involves a little bit of math.
But figuring out the right amount is very important. After all, both dehydration and overhydration can put your health in serious danger.
Don’t worry, though – if you follow these tips, you’ll know exactly how much water to pack for your next hiking adventure, whether it’s a day hike or a backpacking trip.
Then, all you have to do is remember to drink it often enough!