How to Choose a Sleeping Bag

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Nothing compares to a peaceful night’s sleep in the backcountry, but in order to get the beauty rest your body needs, it all starts with choosing the right sleeping bag. From temperature ratings to synthetic fills and even extra features, there are many components of a sleeping bag to consider that will help you determine which bag is right for you. 

From cozy camping bags to lightweight backpacking bags, read on as we deconstruct the sleeping bag so you know how to choose a sleeping bag that’s right for you.

Sleeping Bag Temperature Ratings

Of the many metrics to consider when buying a sleeping bag, the temperature rating is the most important, though other factors such as metabolism, clothing, and sleeping pads will also affect how you really feel once you’re bundled up for the night.

As you begin your search for the perfect bag, think of when and where you’ll use it. If you intend to use your bag in the colder months, look for a three-season bag that can handle low temperatures. If you only plan on using your bag in the dog days of summer, find a bag that’s lightweight and breathable. 

Keep in mind that you can always unzip your bag if you get a little toasty, so it’s best to choose a sleeping bag with a lower temperature rating than the lowest nighttime temperature you expect to encounter.

When it comes to sleeping bag temperature ratings, there will often be two different numbers. One will be the comfort rating, whilst the other will be the EN rating.

EN Rating

The EN rating indicates the lowest temperature at which the sleeping bag will keep you warm. This rating is based on the EN 13537 standard, which means the sleeping bag is independently tested to determine its suitable temperature range. 

Generally speaking, this number refers to the lowest possible temperature in which this sleeping bag can keep you alive. 

When looking to compare one sleeping bag to another, the EN rating offers the best figures for comparison. This is because the EN rating is based on standardized tests, where as each brand may have different ways to assess their own temperature rating.

Comfort Rating

Additionally, the comfort rating of the sleeping bag indicates the lowest possible temperature in which the bag will keep you warm, and as the name suggests, comfortable.

We’ll now cover the different temperature ranges you’ll come accross when looking for a sleeping bag, when they’ll be required and what you can expect from them.

-40° to +4° Sleeping Bags

Camping adventures that involve any form of snow or ice require a sleeping bag that can stand up to extremely cold conditions. These bags will often make use of down insulation as well as draft-eliminating features such as zipper baffles, collars, and hoods. Multi-day ski outings, mountaineering projects, and winter camping trips are common activities that call for a sleeping bag with this temperature rating.

+5° to +29° Sleeping Bags

These sleeping bags are commonly referred to as ‘three-season bags’ because they can be used in almost every environment. Whether you’re car camping in late fall or backpacking in the midst of summer, this is the temperature range you’ll want to select from.

+30° to +55° Sleeping Bags

Summer camping trips and backpacking adventures at lower elevations call for a sleeping bag within this temperature range. These bags don’t require as much insulation or as many heat-saving features to help you regulate your temperature. And because they lack additional insulation and heat-saving features, they’re also the perfect lightweight option for a summer backpacking trip.

Sleeping Bag Shapes

Believe it or not, sleeping bags come in different shapes and sizes that break free from the traditional oblong form. In general, you’ll want to choose a sleeping bag that gives you room to move, which is why so many sleeping bags come in the popular rectangular shape. 

It can be difficult to determine if a sleeping bag is roomy enough for you without crawling into one, so don’t be afraid to try them out at your local gear shop to find one that fits. Sleeping bags come in three distinct shapes that you should know:

how to choose a sleeping bag


Rectangular bags provide you with room to move and groove during the night as you stretch out and readjust. Some rectangular bags can be completely unzipped to act as a blanket if you’re a little warm. 

Semi rectangular bags have rounded corners that make the bag feel like a cross between a traditional rectangular bag and a mummy bag; these offer a compromise between additional warmth and spaciousness.

mummy sleeping bag


A mummy bag makes use of a snug fit around your entire body to keep you warm when the temperatures drop. Many mummy bags feature a built-in hood that makes the sleeping bag feel like a cocoon — the hood works to trap body heat that would otherwise escape through your head.

how to choose a sleeping bag - double

Double Bag

A double bag is made for couples who plan to sleep together. Some rectangular bags can be zipped together to form a double bag, but they need to come from the same brand and model. Chances are you won’t make use of a double bag unless you and your camping partner find the perfect bag that meets both your needs.

Sleeping Bag Insulation Types

Sleeping bags are filled with a material known commonly as insulation that helps to keep you warm, dry, and protected from the elements. There are two major types of insulation on the market today, and both have their own benefits.

Synthetic Insulation

Synthetic insulation is made from polyester fibers that mimic the properties of authentic down insulation. This form of insulation is the more affordable option between the two types of insulation because authentic down is in high demand. 

Synthetic insulation continues to insulate even if it gets damp, and it will dry faster if it’s wet. Because the fibers are artificially made, those that suffer from down-related allergies will be pleased to know that synthetic insulation is non-allergenic.

Down Insulation

Down insulation is more expensive than synthetic insulation, but it’s also lighter and more compressible, making it a preferred choice amongst backpackers looking to save weight. Down also performs well in colder climates, and it’s durable so you can make use of your down sleeping bag for years to come.

Major outdoor brands that manufacture down sleeping bags take steps to monitor the treatment of ducks and geese that provide down. Products labeled with either RDS (Responsible Down Standard) or TDS (Traceable Down Standard) must meet specific standards to ensure the health and well-being of the animal is the top priority.

Down Fill Power

Once you’ve honed in on the sleeping bag that meets your needs, take a moment to consider the fill power. This is a numerical rating system that represents how “lofty” the down insulation is. 

The higher the fill power, the more air that can be trapped within the down itself to keep you warm. For instance, an 800-fill sleeping bag that’s rated for 30° will provide the same level of warmth as a 600-fill sleeping bag that’s also rated for 30°, but it will take more 600-fill down to keep you warm, which means it will be heavier. Essentially, a higher fill power will keep you warmer with less filling.

Common Down Fill Power Values

550 – 600 Fill: This fill power is often found in the most affordable bags for those operating on a budget. It can be relatively heavy and less packable, but it’s still lighter and more compressible than synthetic fills.

700 Fill: This fill power is used in mid-range sleeping bags, and it strikes a balance between overall cost and weight savings.

800+ Fill: These are the most expensive sleeping bags you can buy because they’re ultra-lightweight and extremely packable. Thru-hikers, professional mountaineers, and other serious outdoor elites will often make use of 800+ fill sleeping bags more than others.

Sleeping Bag Weight

Depending on how you plan to use your sleeping bag, you may need to consider its overall weight. For instance, those that intend to use their sleeping bag while backpacking will need a bag that’s made from lightweight, high-quality materials such as nylon. 

The fill power will also need to be higher to provide the same amount of warmth for less weight. Those that are car camping can choose a simpler sleeping bag that has more features and less fill power because overall weight isn’t a primary concern.

Sleeping Bag Length

The length of your sleeping bag is based on your height, and it’s important to find a bag that isn’t too short or too long. If your sleeping bag is too short, your feet will press against the down insulation and compact it over time, in-turn making it less effective. If your sleeping bag is too long, there will be excess room in the bottom that will require more energy to heat up. 

For men that are over six feet tall and women that are over five-foot-six, sleeping bags are available in long models that have more space. It’s acceptable to get a longer sleeping bag if you’re looking to store gear that needs to stay warm in your footbox, such as boot liners or important electronics.

Sleeping Bag Features & Extras

A sleeping bag made from sustainably sourced down is nothing without a few additional features that can make it the perfect cozy cocoon for every backcountry occasion. 

A sleeping bag made from sustainably sourced down is nothing without a few additional features that can make it the perfect cozy cocoon for every backcountry occasion. 

Additional features to consider include: 

  • A sleeping bag shell that will shed water and protect your bag’s insulation.
  • Built-in stash pockets to store much-needed items like lip balm or electronics.
  • A sleeping bag hood that makes any bag more snug-fitting. 
  • Left & right handed zips – allows you to enter and exit the sleeping bag with ease.
  • Two-way zips are ideal for adding some ventilation for warmer nights.
  • A zip baffle will help to insulate the zip of the sleeping bag, which can allow heat to be lost.

Keep on the lookout for bags that make use of these simple features when the time comes to choose a sleeping bag.

Sleeping bag extras include compression sacks to pack down your bag for transportation, as well as sleeping bag liners that slip inside your sleeping bag for additional warmth and protection. If you’re sleeping in insufferable heat, ditch the sleeping bag and sleep in the liner instead.

Setting a Sleeping Bag Budget

Before you can even think about any of the specs we’ve discussed above, you’ll need to set a budget that will help you find a proper bag without breaking the bank. Super-lightweight, ultra-portable bags may catch your eye, but they’re overkill for most of us. 

Plus, they can quickly leave a hole in your wallet if you’re not careful. Determine how much you can afford to spend, then review the sleeping bags that fall within your budget.

Don’t Forget About the Sleeping Pad

Your top-of-the-line sleeping bag is nothing without a sleeping pad that will keep you warmer by insulating you from the cold ground. Avoid flimsy pieces of foam and find a sleeping pad that’s approximately two inches thick or more. This will keep you warmer, and you won’t feel every rock and twig under the tent when it’s time to hit the hay.

Final Thoughts

Considering the importance of a sleeping bag, the buying process is not one to be rushed. 

Taking your time to assess your needs and requirements, and finding a bag to meet these is incredibly important. 

Hopefully our guide on how to choose a sleeping bag will have prepped you on the various different aspects to be taken into consideration. If you do have any questions, please feel free to get in touch via the comment section below.


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