When hiking, the amount of water you take depends on your body weight and the hiking distance you are going to be travelling.
Surprisingly, most hikers still do not carry or drink the recommended daily amounts for their hike activity, temperature, and body weight.
But how much water should you take on a hike?
The body requires 2 liters of water for every 4 hours hiking. This should increase by 20% for temperatures exceeding 77F. If your hike is strenuous, you should consume 4 liters of water for every 4 hours hiking.
Personally, I am not a massive fan of drinking water at any time. It becomes easier when hiking, but this is probably because your body is literally calling out for it.
Although this amount of water intake is a general guideline, there are other factors to take into consideration.
In this post we will look at water intake you need, how much you should take plus alternatives and essential tips to staying hydrated even when water is scarce.
How to calculate how much water to carry on a hike
We all know how vital it is to stay hydrated on a hike.
It helps keep us moving, focused, and motivated as well as making for a much more enjoyable hike without needing to fight more fatigue than necessary.
The recommendation is between 3 and 4 liters of water a day, depending on your activity level, fitness level and the outside temperature – if it’s an overly strenuous hike, this should be around 6-8 liters.
Here is a handy table to show how to calculate how much water is needed for a hike:
| Hike Duration | Outside Temperature | Water Required |
|---|---|---|
| 2 Hours | Less than 77F | 1 liter |
| 2 Hours | Above 77F | 1.5-2 liters |
| 4 Hours | Less than 77F | 2 liters |
| 4 Hours | Above 77F | 3-4 liters |
| 8 Hours | Less than 77F | 4 liters |
| 8 Hours | Above 77F | 7-8 liters |
| 2 Days | Less than 77F | 8 liters |
| 2 Days | Above 77F | 14-16 liters |
I don’t know if you have ever tried to carry 8 liters of water, but it is heavy!
The challenge though is not overloading your backpack with lots of water meaning an unstable pack, as the water shifts around. It can cause injury to you, especially if it makes you unbalanced.
Also carrying around a heavy load whilst hiking can ruin the experience. How though can you get the balance right?
It is important to have plenty of water on hand in case it is hard to find even if you have a water filter, or you get lost.
The amount of water you will need on a hike is based on four distinct variables:
- The length of your hike
- How strenuous your hike
- The outside temperature
- Your body weight and fitness level
Of course, the longer and more strenuous your hike, the more water you will need.
The hotter the temperature, the more you will sweat, and you become dehydrated faster, so again more water is required.
How much water do I need for a 10-mile hike?
So far, we have looked at lots of data, numbers, and calculations – but let us put all this water math into some meaningful examples.
In this example we will use a 10-mile hike across a relatively stable and established trail, in 70-degree heat.
A 10-mile hike will take an average of 4 hours to complete.
Considering the temperature is not going to exceed 77-degrees Fahrenheit, and the trail established and not too strenuous, then you will need 2 liters of water for a 10-mile hike.
I have done a lot of long hikes in my life, but I remember the first time I completed a 10-mile hike.
It is not super difficult if you keep your head down and keep moving.
The trail was on the West side of the lake in Banff, which made the view pretty amazing.
Don’t be daunted by a 10-mile hike if it is your first time. Be prepared and take plenty of water, and you’ll be just fine!
How much water should I bring on a 2-day hike?
In the last example we looked at a specific distance, but for this example we will look at a time frame instead, and how much water you should bring on a 2-day hike.
An overnight hike is an amazing experience. There is just something so liberating and mind-refreshing to undertake.
You will need to drink 8 liters of water on a 2-day hike. If your hike is particularly strenuous, or the temperate above 77 degrees Fahrenheit, you may need to adjust this, and increase your water intake.
This is a lot of water to take of course, and not very practical to carry around with you.
The muscle impact alone of 8 liters of water could do your body damage, just like dehydration will.
There are other ways to stay hydrated on a hike without the need to take bottles and bottles of heavy water, which not only will slow you down but could make the hike itself very uncomfortable.
Hiking is supposed to be fun!
If you know in advance you will find water sources on your hike – Google Maps is a good way to check this – you may be able to take tools to light a fire and boil the water found or use filters and purifiers to make water safer to drink.
How to find safe drinking water on a hike
If you are planning a 3 day or more hike, you will struggle to take with you the amount of water you need.
A 3-day hike would mean an average of 12 liters of water!
No water found on a hike should be consumed without a filter or treatment.
Bacteria in streams, lakes and rivers is common, particularly in North America, so you will need to treat the water first before you drink.
There are two ways to treat water found on a hike:
- Filters
- Purifier will remove bacteria and viruses
Water Filters on a Hike
A water filter should be part of your hiking gear.
It is used to filter out, in the main, bacteria from water sources when outdoors, like hiking.
A filter, such as pump filter for example, eliminates the bacteria and other impurities as you pump the water from source. The pump ‘cleans’ the water and passes just the safe clean water through into the water bottle. This is a good idea for solo travelers.
A gravity water filter, for example, is better for times you need to have clean water for more than one person, or a group.
Water from source is placed in one bag, which connects to a second bag through a filter. Simply hang the bag with the dirty water at a higher elevation to the other, and gravity will feed the water to the second bag through the filter – giving just clean drinkable water in the second bag.
It should be noted though that a water filter will not filter out any viruses. This is less of an issue in North America, but if you are hiking outside of the US and Canada, particularly in places where viruses and animal viruses in the outdoors are common, you should opt for a water purifier.
Water Purifiers for Hiking
Water purifies take one step further by removing not only bacteria but harmful viruses too.
These can be used when you really want to be on the safe side, but water filters are commonly used throughout the US.
An example of a water purifier is a UV purifier.
It is small and lightweight but by stirring a UV purifier in untreated water will neutralize the water and remove those harmful viruses and bacteria that may be lurking around. The do require batteries though, so consider this when it comes to space – and take extra batteries with you!
A UV purifier can be used in combination with a water filter.
There are chemical water purifier treatments available. These work well, do not require batteries and easy to store, but you can wait up to 3-4 hours for treated water to be safe to drink.
Not particularly useful if you are really dehydrated and have finally managed to stumble across a water source on your hike.
This good demonstration video explains about filters and purifiers, the types and show you what type of products you need:
How safe are water filters and purifiers?
The water filters and purifiers sound a great idea, and can really help reduce the amount of water you need to take with you on a hike – but just how safe are water filters and purifiers for hiking?
According to the Centers for Disease Control and Prevention website the best way to clean any water is to boil it.
Boiling water will kill harmful bacteria, viruses, and parasites.
It isn’t always the most convenient or efficient way to obtain drinking water. Time will be spent to setup the fire, boil the water, and wait for it to cool properly to be able to drink.
The CSC do recommend using a filter system that has a ‘filter pore size small enough to remove parasites’.
CSC do confirm that filers do not remove viruses, as we know – but also state that most filters do not remove all bacteria. A filter with a NSF Standard of 53 or 58 will remove parasites if done right, but not viruses and not all bacteria.
UV purifiers are effective for cleaning small amounts of clear untreated water, but less effective for cloudy untreated water as the particles floating in the water may block the light that is being used to purify.
Boiling is the recommended option, according to the CSC, but if this is not an option then try to use a combination of filter and purifier – to be on the safer side – for cleaner water to drink.
Water Bladder vs Water Bottle for Hiking
There are two main containers for carrying water on a hike These are a standard water bottle and a water bladder.
The main difference between them is that a standard water bottle will keep the same shape whether full of water or not, where as water bladder will reduce in size as the water inside is consumed.
A water bladder can be really useful to store once the water is gone. Once empty they take up less space in your backpack.
Usually, water bladders come with a handy drinking long hose which means you can drink water from a tube whilst hiking, without stopping to take a water bottle out from your backpack.
I have tried and tested both and I do prefer the water bladder over a water bottle.
I love the nozzle and hose to drink from, and it just does not need as much room for storage once you’re done. A caveat to this though is they usually take up more storage than a water bottle when full – so it may depend on how long your hike is, and how much water you will need.
A water bottle also be heavier empty than a bladder. A large water bottle can weigh 6oz when empty, compared with 2-3oz for a water bladder.
Using Hydration Packs
Hydration packs are an all-in-one efficient solution to water requirements while out hiking.
There are different brands on the market but essentially these are designed for travel light hikers but can carry up to 28 liters of water!
28 liters of water will weigh approx. 30kg. If you have ever tried lifting a 30kg barbell, it’s heavy.
There are smaller versions available in sizes of around 8 liters and 14 liters, depending on the brand.
If you are planning on an overnight hike, or a few days hiking, and don’t know if you are likely to find water to boil, filter or purify along the way, this can be a much-needed part of your trip.
You need to make sure you will be comfortable with the weight of one of these when full.
1 liter of water is equal to approx. 1kg – plus the weight of the backpack or container it is in.
If you know you can find water to drink on your hike, you may be better off with filters but if water is likely to be an unknown on your hike, then a hydration pack can make sure you are better prepared.