What Is A Sleeping Bag Liner And Do You Really Need One?

Are sleeping bag liners useful or just a waste of money?

A sleeping bag liner is essentially a smaller, lighter version of a sleeping bag. The liners are inserted into sleeping bags to protect the sleeping bag from getting dirty, as well as to add warmth to the bag. Campers can save money and have a more comfortable sleeping experience with the help of sleeping bag liners.

Sleeping bag liners can sometimes seem like an unnecessary expense. However, they can save you from having to wash or replace your sleeping bag quite as often. In this way, you can think of a sleeping bag liner like bed sheets.

By the way, as an Amazon Associate, I earn when buying qualified products through links on my site.

The materials in sleeping bags can have a tendency to absorb the smells they come into contact with. So, year-old campfire smell? Maybe. Year-old hiking body odor? Nah…

I’ve put together some information that can help you to determine whether or not a sleeping bag liner could be useful for you.

What’s A Sleeping Bag Liner?

A sleeping bag liner is essentially a lightweight version of a sleeping bag. Typically, these liners are thinner and offer more variety than many sleeping bags, including numerous materials, thicknesses, and sizes. Whether you’re looking for a little extra warmth or something to increase the durability of your sleeping bag, a sleeping bag liner is a great solution.

Meraklon Sleeping bag liner from Subzero. Image from Flikr with this license

Using a sleeping bag liner consists of placing the liner inside the sleeping bag. When you crawl into bed after a long day of camping or backpacking, your body is in contact with the liner, but getting the full insulation of your regular sleeping bag.

Additionally, in warm weather, you can get by with just using the sleeping bag liner by itself without the sleeping bag.

What’s The Point Of A Sleeping Bag Liner?

To some, a sleeping bag liner can seem a bit excessive. However, they can actually be really useful. In short, sleeping bag liners can help your sleeping bag to last longer, save you money on replacements and cleaning, and even make your nights more comfortable. The following are a few in-depth reasons for how a sleeping bag liner can improve your camping experience.

Sleeping Bag Hygiene

Part of the fun of camping is that it gets a little dirty. I don’t know about you, but to me it’s fairly common to crawl into my sleeping bag with dirt, sweat, and campfire smoke all over.

Now, without any extra layer of protection, all that just goes right into the sleeping bag from your body and clothes (if you sleep in your clothes).

However, with a liner, there IS another option: Rather than allowing dirt and grime to become embedded into the inner layers of their sleeping bag, you can use a sleeping bag liner. As a result, you only need to run that liner through the wash once you get home instead of cleaning the entire sleeping bag.

Sleeping bags are heavy and difficult to wash. The ability to wash a liner instead makes your post-camping cleanup a lot easier. Additionally, the use of a liner keeps you from having to replace your sleeping bag as often. The cost of an entry-level sleeping bag can easily reach $100 or more, whereas sleeping bag liners are often half that cost or less.

Consequently, spending a little more to use a sleeping bag liner will save money over time.

Here’s something you may not have thought about before – how long does a sleeping bag actually last? Sometimes, it can seem like they can last forever as long as they aren’t damaged in some way. To learn more about how long sleeping bags last, check out our article on the topic here.

A Better Sleeping Experience

Although sleeping bags are often designed for warmth and durability, they aren’t always the most comfortable. The materials used aren’t typically intended to feel like your Purple ™ mattress at home. For a long time, sleeping bags were seen as part of wilderness survival – with comfort as a priority being a fair bit behind survival.

However, things are much different today. While sleeping bags are still useful for survival, they are more often used during camping and backpacking trips. Since casual camping is not so much a struggle to survive, it makes sense that you might want a more comfortable bed during their outdoor adventures.

Sleeping bag liners are an easy way to create more comfort. They are lightweight, relatively inexpensive, and come in a wide variety of materials. As a result, it’s easy to choose a sleeping bag liner that will make your sleeping bag feel more bedlike. Whether you prefer the comfort of cotton or the coolness of silk, there are liners on the market that can help give the feeling of bedsheets, making for a better sleep.

Added Warmth

You never know what turns the weather might take while you’re out on a camping trip. Let’s say you’re prepared for lows in the 50s, but forget about the temperature dips that can happen overnight. A sleeping bag liner can make the difference between a night on the edge of misery and a nice, dreamless sleep.

Liners are especially useful if you aren’t expecting extreme temperature changes, but want to make sure you’ll stay warm if there are smaller shifts. Depending on the material, sleeping bag liners can aid in regulating temperature if things get too warm. I’ll go into the specifics of just how much liners can help in surprise temperature shifts a little further down.

Repelling Bugs

Perhaps you didn’t know this, already, but one of the big benefits of certain sleeping bag liners is to repel bugs.

Sea to Summit makes a sleeping bag liner that’s combined with insectshield.com technology–one more way to keep the bugs at bay while sleeping.

Do I Really Need A Sleeping Bag Liner?

You don’t need a sleeping bag liner. They are definitely in the nice-to-have category.

Ultimately, whether or not you use a sleeping bag liner is entirely up to you. There are lots of people out there who may not camp frequently enough to worry about the accumulated camping smell in your sleeping bag. However, there are others who swear by sleeping bag liners due to their benefits.

For all my years of camping I’ve never used a liner and just dealt with the ripe sleeping bag. It’s definitely an optional thing and you can get by without it.

In my research, I discovered that campers, backpackers, and cyclists often choose to use sleeping bag liners to add warmth to their sleeping bag. Some may also use a sleeping bag liner in place of a sleeping bag when spending time in hotter areas.

Additionally, if you want to save money, you can make your own sleeping bag liners. You can choose whatever fabric you want! Just fold over a bedsheet and sew the edges together and you have a sleeping bag liner! Or, you can use a thin fleece if you’re more concerned about adding warmth.

What’s the Downside Of Liners?

Well, besides yet another thing to pack in, I also discovered that some people experience getting tangled in their sleeping bag liners, with more fuss getting into and out of their sleeping bags. This is more true of more restrictive sleeping bags (like mummy bags).

There are lots of sleeping bag designs, actually, that are meant to be more roomy and accessible (esp. for those who sleep on their sides). You can learn more about different sleeping bag designs here if you have been feeling like you want to sleep with more space.

What Types Of Fabrics Are Used In Sleeping Bag Liners?

We tend to know what to expect when it comes to sleeping bag materials. Most often, sleeping bags are intended for different levels of warmth. On the other hand, sleeping bag liners can help to cool you down at night, offer you a more bedlike experience, and even wick away sweat.


A common go-to, cotton sleeping bag liners like the TETON (Amazon) are reliable choices. Cotton is best suited for mild, warm temperatures. Although cotton is absorbant, if you have a very thin cotton layer, the moisture is going to stay on your skin–not a great experience.


Polyester, microfiber, and fleece are just a few of the options you might find while shopping for a synthetic sleeping bag liner. Cabela’s Getaway liner is an example of a fleece liner if extra warmth is your top priority. Depending on the exact material you choose, synthetics can be extremely durable, flexible, and moisture-wicking. Depending on the thickness of the fabric, some also allow the breathability needed to stay cool at warmer temperatures.

You can learn more about fleece vs wool, here, where we do an in-depth comparison.


Raw wool

While wool might be one of the more expensive sleeping bag liner options, wool is great at moving moisture from your skin and retaining it. As a result, it’s easier to enjoy a comfortable sleep in a wide variety of temperatures. Some varieties of wool can also dry quickly, making them more suitable for damp conditions. Options like the Smartwool Merino liner are great for staying warm and dry.



For camping in the heat, a silk sleeping bag liner like the Browint (Amazon) are great for staying cool throughout the night. No one wants to add too much to their pack when it’s going to be hot out. Luckily, silk liners are very lightweight. The Browint itself weighs in at 5 ounces, even though it’s designed for large sleeping bags.

Can You Get By With Just The Sleeping Bag Liner?

For hot weather, you can get away with leaving your sleeping bag at home- instead choosing the lightweight convenience of a sleeping bag liner. That said, there are a few factors worth taking into account if you’re considering sleeping in only a sleeping bag liner.

These factors include the following:

  • Nighttime temperatures. Without the sun, your campsite may get colder than you expect. Check the temperature forecasts specifically for overnight hours to make sure you’ll be warm enough. I personally wouldn’t camp with just a liner if the temperatures are going to dip into the low 60s (Fahrenheit).
  • Shade and wind. Strong breezes can make it feel colder. If the area you plan to camp in tends to be windy, consider bringing extra blankets for warmth. The same applies to areas with a lot of shade.
  • Liner material and thickness. Not all liners will work in the same conditions. Taking a silk liner out in mild temperatures will likely leave you shivering overnight. Make sure to take a liner that will keep you warm enough. Cotton and fleece are often solid options.
  • Weather conditions. Wet weather will also leave you feeling much colder. So even if the temperatures are mild (60s and 70s), I’d bring a bag if there’s any chance of getting wet.

Overall, as long as the weather is warm and you’re dressed properly, it is totally possible to get by with just a sleeping bag liner.

One example: I went camping in South Texas during the heat of the summer. The low temperature was in the high 70s. Because we were in Texas with all the bugs and scorpions, we slept in a tent–and it was pretty miserable. I slept on top of my sleeping bag, even though it felt weird to not sleep with a blanket of sheet on top of me. A liner would excel in this type of situation.

How Much Warmth Does A Sleeping Bag Liner Add?

Sleeping bag liners work well as a step between your regular sleeping bag and a sleeping bag intended for cold weather. The range for sleeping bags is often much larger, so some may find that sometimes their normal sleeping bag isn’t quite warm enough. If you don’t want to spend the money on a cold weather sleeping bag – or are concerned it might be too warm – a sleeping bag liner can work as a happy middle ground.

According to REI, using a liner can add anywhere from 5 to 15 degrees to the inside of your sleeping bag.

(Remember, a sleeping bag temperature-rating is not really rated for comfort, it’s rated for survival)

So, as a reference, if you have a sleeping bag rated to 50 degrees, then you have a chance of being comfortable with a liner sleeping in 50 degree weather. Just keep in mind that the liner material you choose makes a big difference in the added warmth you get.

Those who frequently camp in hotter areas may be more concerned about staying cool while camping. Even the coolest sleeping bags can lack breathability, leaving you feeling sweaty and uncomfortable at night. To find out how to avoid this issue, take a look at our article on the subject here.

How Much Should I Expect To Spend On A Sleeping Bag Liner?

Sleeping bag liners come in a wide range of prices. Quality, materials, and size all play a role in how much a liner may cost you. In my research, I discovered that the majority of sleeping bag liners will come in at under $100. From there, you’ll be able to find liners for just about any budget.

Those who want something simple can look for options like the Vumos, which is made from polyester. Meanwhile, those who want something for more intense situations would benefit from the Thermolite Reactor from Sea To Summit. No matter what you’re willing to spend, there are numerous liners out there to choose from.

Replacing an old liner is much easier than replacing an entire sleeping bag. They’re also much easier to clean. Most sleeping bag liners can go right into the washing machine after a trip, whereas sleeping bags require a lot more effort to get clean–for example: how do you go about it? Can you use your regular top-loading washing machine? Can you use regular dish detergent? Take a look at our article on the topic here to learn more about getting your sleeping bag clean.


Peter is a software developer who loves to take every opportunity to go outside that he can get. Peter grew up going on long backpacking excursions with his family every Summer and now enjoys staying at the beautiful Texas State Parks and swimming in the amazing Texas Rivers.

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