How Much Water to Bring On A Hike? A Definitive Guide

Staying hydrated during hikes is essential. Unfortunately, many trails you’ll encounter while hiking won’t have reliable water sources, so knowing how much water to carry during your hikes before you hit the trails is always a good idea. That said, how much water to bring on a hike depends on several factors – and we’ll get into it all here.

How Much Water per Hour of Hiking?

The general consensus is to drink at least 500 ml of water per hour when hiking. This obviously can vary depending on the difficulty of the hike, the weather conditions, your physiology, etc. We’ll get into

So how much water to bring then? A good rule of thumb is to take 1 liter (1000 ml) for every 2-3 hours you expect to be hiking.

Factors that Affect How Much Water to Bring on A Hike

Although the general guideline says to drink and carry at least 500 ml of water per hour, there are several factors that you should consider when determining EXACTLY how much water to bring on a hike. We’ll list them first and then get into how it affects your water requirements.

• Age 
• Body Weight and composition
• The intensity of the hike
• Duration of the hike
• Weather
• Trail difficulty 
• Water sources on trails

Body Weight and Composition: The first factor is your own physiology – your body weight and composition. Obviously, the more you weigh, the more water you’ll need to drink to stay properly hydrated. But it’s not JUST your weight. Your muscle composition also has a significant role in how much water you’ll need to drink.

The fitter you are, the more muscle mass you likely have. Muscle holds water better than fat, so you won’t need to drink as much to stay hydrated if you’re carrying more muscle on your hike!

Age: As we age, our sense of thirst decreases. So although you might have been able to get away with only carrying a liter or two of water when you were in your 20s, doing the same hike in your 30s might require double the amount of water.

The intensity of the hike: The steeper and more challenging the hike, the more water you’ll need to drink to stay hydrated. This is because you’ll be sweating more and losing more fluids.

Duration of the hike: The longer the hike, the more water you’ll need to bring. This one is relatively simple to figure out, and you can go by the calculations above. (500ml per hour) Even if the hike isn’t particularly challenging, being out in the sun for an extended period of time will dehydrate you.

Weather: The hotter the weather, the more water you’ll need to drink to stay hydrated. You’ll sweat more in hot weather, and sweating is how your body regulates its temperature. Make sure to drink more water than usual if you’re hiking in hot weather! Another potential risk of dehydration in the sun is heat stroke, which can sometimes be fatal.

Trail difficulty: If the trail is more difficult, you might need to stop and take breaks more often. These breaks are a perfect opportunity to drink some water and rehydrate yourself.

Water sources on the trail: If the trail has reliable water sources, you can drink from them as needed and top off your water bottle. But just note that you’ll most likely need to purify the water first.

It’s not rocket science by any means, but because of all these variables, there’s no one-size-fits-all answer to how much water you should bring on a hike. Use your best judgment, and if in doubt, err on the side of bringing more water rather than less.

What Else Can You Do?

Before setting out on your next hike, aim to drink about a liter of water. Drinking water beforehand essentially prepares your body for the fluid it will lose during the hike and helps cut down the water you’d need to carry on your hike.

Secondly, do your research. Try to look out for guidebooks and road maps. They will make you more familiar with the trails and know what to expect during your hikes. The guides should point out if there are water sources on the trail. Abundant water sources can reduce the amount of water you need to carry, making your hiking expedition lighter and easier.

If you want to cut down on the weight of your water even further, consider using a water filter or purifier. These can be used to cleanse water from natural sources, making it safe to drink without carrying as much with you.

How Much Water Can a Person Carry on A Trail?

So if you did the math here, it looks like going on a long, strenuous trail out in the sun will require gallons upon gallons of water. That’s a lot of water! So how the heck do you carry all of that? The simple answer is that you don’t. The average person can only carry about 3-4 liters of water at a time, which isn’t nearly enough for some hikes.

So what do you do?

That’s why it’s essential to know where the water sources are on the trail and whether or not you can rely on them.

If there are water sources, you can carry less water and refill as needed. But if the trail is in a remote area with no water sources, you might need to consider carrying a larger water reservoir or even bringing along a water filter, and sometimes both.

Typically, a hydration bladder is the best way to carry larger amounts of water on a hike. A hydration bladder is a large, water-tight bag that fits in your backpack and has a small tube attached to it. This tube allows you to drink hands-free while you’re hiking.

Recommendation For a good Hydration Bladder – I recommend this hydration bladder by Osprey. It can carry up to 3 liters of water and is very beginner-friendly.

Another option is to use a water filter or purifier. These can be used to clean water from natural sources, making it safe to drink without carrying as much with you.

Recommendation For a great water filter – I recommend the Katadyn Hiker Pro Transparent Water Filter. It’s a bit on the pricey side, but also very easy to use and comes with both pump and filter.

Is There Such a Thing as Too Much Water While Hiking?

Your brain and body clearly need water to function. But did you know that it’s possible to drink too much water?

It might sound counterintuitive, but it’s true. When you drink an excessive amount of water, your body’s sodium levels drop dramatically, which leads to an imbalance of electrolytes. This condition is called hyponatremia, and it can be just as dangerous as dehydration.

Hyponatremia can cause nausea, vomiting, headaches, fatigue, and confusion. It can lead to seizures, coma, and even death in severe cases.

You can also experience a disruption of brain functions if too much water in the brain cells causes them to swell. This pressurizes the brain, and you may start experiencing headaches and drowsiness. If the pressure continues, it could lead to a low heart rate.

Although it is very rare, it’s still something to be aware of and take seriously. To prevent this, you should monitor how much water you’re drinking and supplement with electrolytes if needed.

Can You Drink Gatorade Instead of Water?

So if electrolytes are important, does that mean you can just drink Gatorade or another sports drink instead of water?

Gatorade and other sports drinks do contain electrolytes, but they also contain a lot of sugar. In fact, a 20-ounce bottle of Gatorade has 34 grams of sugar. That’s more than the daily recommended intake for most people!

Plus, the electrolytes in Gatorade are in a very concentrated form. When you drink too much of it, you can end up depleting your body’s electrolyte levels.

So while Gatorade can be helpful in moderation, water is still the better choice over Gatorade for hydration while hiking.

Recommendation If you think you’ll need the extra electrolytes, I recommend Electrolyte Tablets from Nuun. They come in different flavors, but my favorites are the Tri-Berry and Lemon Lime. They are easy to use and don’t add any sugar or calories to your water. Simply drop a tablet in water and it’ll dissolve within minutes. These have been my go-to for years. As a bonus – they’re great for treating hangovers too! 😉

What’s the Best Temperature for Hiking Water?

Ideally, you want your water to be nice and cool when you’re out on the trail. But what’s the best way to keep it that way?

There are a few different options:

1. Use a hydration bladder with an insulated tube. This will keep your water from getting warm as it sits in your backpack.

2. Fill up a reusable water bottle with ice before you head out. As the ice melts, it will keep your water cold. Just be sure to drink it before it all melts!

3. Bring along a small cooler with ice packs. This is a good option if you’re hiking in hot weather and want to keep your water (and other food) from getting too warm.

4. Use an insulated water bottle, such as a Hydroflask or a Yeti. These bottles will keep your water cold for hours.

Recommendation Personally, I can vouch for Hyrdoflask, specifically the 32 oz. Hydroflask. This is the exact one I’ve been using for years, and I’ve been a happy camper (no pun intended).

Water Requirements By Popular Distances

How Much Water Do I Need for A 10-Mile Hike?

A 10-mile hike can take between 6 to 12 hours, depending on the terrain, temperature, and pace at which you walk. Please don’t underestimate how long a mile takes to travel when it comes to hiking! If you are not familiar with the trail, you may need to add an extra liter of water.

I would recommend 6-8 liters of water.

How Much Water Do I Need for A 4-Hour Hike?

For a beginner, you will need about 2 liters of water. However, if you are experienced and familiar with the trail, you can consider a lesser quantity of water.

On rocky trails and during summer, you can consider adding an extra liter of water. If you’re prone to sweating, you might want to bring even more. If that’s the case, I recommend 3-4 liters of water.

How Much Water Should I Bring on A Day Hike?

The amount of water you need for a day hike will depend on the factors mentioned earlier, such as terrain, temperature, and your hiking pace.

As a general rule of thumb, you should plan on bringing 1 liter of water for every 2 hours of hiking.

So how long is an average day hike? Most day hikes are between 3-8 hours. If you fall into that range, you should plan on bringing 1.5-4 liters of water.

Of course, this is just a general rule. You may need more or less water, depending on the specific conditions.

How Much Water Do I Need for A 1-Mile Hike?

For a simple 1 mile hike, you will need about 500 ml of water. If the weather is hot, you may want to bring 1 liter of water.

Conclusion

So, what does all of this mean for you? It’s essential to stay hydrated when spending time outdoors. Not having enough water while hiking can be quite dangerous. Make sure you consider the factors we’ve mentioned – such as heat, humidity, and altitude – to ensure that you drink enough water to avoid dehydration. And don’t forget to bring along a reusable water bottle to keep sipping on fluids even when you’re not near a source of freshwater!