How to Choose a Sleeping Bag


One of the core items in any camper’s setup, a good sleeping bag is something that all of us will need eventually. However, considering the vast number of options available, the process of choosing the proper bag can feel overwhelming at times. Will it be warm enough? Will it be portable enough? Will I be able to fit inside?

These are common questions, and they’re all entirely valid. So, to help you purchase with confidence, here’s the complete guide on how to choose a sleeping bag for your next outdoor adventure.

Key Takeaways:

  • Rectangular bags are roomy but bulky – ideal for car camping.
  • Mummy bags are compact, lightweight – excellent for cold environments or backpacking.
  • Semi-rectangular bags offer a middle ground between roominess and portability.
  • Quilts, while not traditional sleeping bags, are versatile alternatives.
  • Down is lightweight and warm; synthetic is budget friendly.
  • Temperature ratings indicate the lowest “comfortable” temperature for a sleeping bag
  • Compression sacks and optional extras can be valuable.

Different Types of Sleeping Bags


Important Features


black sleeping bag on a blue sleeping pad

Sleeping bags come in three different shapes: rectangular, mummy, and semi-rectangular. Each shape has its own set of merits, and they all perform best in certain environments. That being said, let’s dive in and explore the differences.

For starters, rectangular sleeping bags look just like the name implies. They’re often large and boxy, providing a significant amount of room for spreading out and getting comfortable during the night. However, the tradeoff is that they’re heavy and bulky, making them somewhat difficult to squeeze into a backpack and carry long distances. That’s why I usually recommend campers only invest in a rectangular sleeping bag if they plan on doing a lot of car camping, where they won’t need to travel long distances with their gear.

On the other hand, mummy bags hug your body like a glove, providing little room for you to stretch out. While they aren’t nearly as comfortable as rectangular bags, they do compress down to a much smaller size, and they tend to weigh significantly less. Since there isn’t as much space inside the bag, it’s much easier to stay warm inside it as well, because of the lack of ambient air surrounding you. Whether you’re camping in a cold, alpine environment or you’re going on a backpacking trip, a mummy style bag is the way you’re going to want to go.

Semi-rectangular bags try to combine the best of both worlds. They aren’t as roomy as a real rectangular bag, so they’re more portable and do a better job at keeping you warm. At the same time, they aren’t as confining as a mummy bag either. While this style does provide a nice middle ground, I would just treat it as a warmer (and smaller) version of a rectangular bag. You can backpack with some models, but generally speaking, I’d only use a semi-rectangular bag for car camping.

And finally, as a brief aside, you could always go with a quilt as well. While not technically sleeping bags, quilts still provide a good deal of warmth, and they tend to be a lot more versatile. You’ll find that most have a footbox and straps that allow you to connect it to a sleeping pad, so in a lot of ways, you can treat it like a normal sleeping bag.

Insulation Type

woman sitting in a tent with a blue sleeping bag

Every sleeping bag has a fill, which provides insulation against the cold. The two you have to choose from are down and synthetic, which are about as different from each other as you can possibly get.

On the one hand, you have down, which is what I consider to be the superior insulation type. It’s very lightweight, compresses down better than synthetic, and provides a greater amount of warmth with less material. The downside is that it loses its insulation capabilities when wet, so it’s not as great when you’re in a humid climate or if you experience a lot of condensation falling from your tent ceiling. However, hydrophobic down is becoming more and more common, and while it’s a lot more expensive, is does solve the insulation problem when down gets wet.

On the other hand, you have synthetic, which is heavy, bulky, and won’t keep you as warm as down. But it’s not all bad, since synthetic really shines when it comes to cost effectiveness and its ability to continue insulating while it’s wet. So, if you’re a car camper on a budget, a bag with a synthetic fill is definitely the way to go.

Temperature Rating

inside of a sleeping bag
Season/ConditionTemperature Rating (Fahrenheit)
Summer30+ Degrees
3-Season15-30 Degrees
Winter15 Degrees or Less
Alpine15 Degrees or Less

Temperature rating refers to lowest temperature it can be outside for you to still be safe and “comfortable” inside of your sleeping bag. More specifically, if you have a sleeping bag rated for 35 degrees, that means temperatures can drop that low before you need to start hugging yourself for warmth. Will you be loving life? Probably not. Will you be kept alive all night? Almost certainly.

That being said, my recommendation is that you don’t push a sleeping bag to its temperature limit. Always give yourself at least 10 degrees of buffer, unless you plan on using a sleeping bag liner to push the temperature rating even lower. In practice, that means you shouldn’t camp in climates that will drop below 45 degrees, if your sleeping bag is rated for 35 degrees. I’d rather you be too hot than not warm enough, especially when you’re dealing with the possibility of hypothermia in extreme conditions.

Now, it is worth noting the difference between tested lower limit and tested comfort. You might see one or both of these ratings listed with a particular sleeping bag, but they essentially mean the same thing – it’s just that one is for men and the other is for women. The tested lower limit is generally considered the coldest it can be for a man to be “comfortable” inside his sleeping bag, while the tested comfort rating is the coldest it can be for a woman to stay “comfortable.” Still, take the numbers with a grain of salt. Every person has a different tolerance for certain temperatures, so if you don’t handle the cold well, give yourself a much bigger buffer.


black sleeping bag compression sack

Most sleeping bags don’t come alone. At the very least, you can expect them to come with a compression sack to make transportation easier. Some of the fancier models will also include a mesh storage sack, which is much larger than a compression sack. Storing your sleeping bag in a tightly compacted space is bad for the insulation, which is why it’s so handy to have a storage sack as well.

But, in addition to storage, you’ll also find some sleeping bags that come with a few other trinkets. The NEMO Jazz, for example, comes with its own set of bedsheets for an ultra-luxurious camping experience. Others have their own sleeping bag liners as well, to give you that extra warmth on those super cold nights. While these aren’t mandatory additions, they certainly do come in handy, if you’re willing to spend a little extra for the equipment.

Additional Features

woman putting a phone in a sleeping bag pocket

If you want to know how to choose a sleeping bag, there are a few key features that you’ll want to look out for. Some of the more common ones include:

Double Sleeping Bags. Want to share a sleeping bag with your partner? Double sleeping bags do exist, and they can be a great option when you want to snuggle up with your loved one/s while camping. While there are a few that come as one giant sleeping bag, it’s more common to find single person sleeping bags that can combine with another to create a double. Some come with a zipper on the left side of the bag, which can be combined with a sleeping bag that has a zipper on the right side.

Pockets. Many sleeping bags come with internal pockets, which give you the space needed to store your phone (or other small belongings) close by.

Hood. Mostly seen on mummy bags, the hood goes over your head to seal in as much heat as possible. When you’re wearing it, only your eyes, mouth, and nose are exposed to the outside air, though in some cases, even more of your face might be covered than that.

woman in a sleeping bag with a zipper

Multiple Zippers. On a sleeping bag, you obviously have the zipper that allows you to get into the bag in the first place. But in addition to that, some bags might have another zipper around the feet, allowing you to ventilate the bottom of the bag when it gets too hot.

Draft Tube. This is an insulated tube that runs along the length of the sleeping bag. Since zippers are notorious for letting cold air leak inside your sleep system, the draft tube helps prevent this from happening.

Pillow Pocket. Not all sleeping bags have this, but a pillow pocket is a sleeve that you can put your camping pillow inside of at night. It keeps the pillow from moving around, which ultimately helps you get a better night’s rest.

Sleeping Pad Straps. Some sleeping bags also come with straps that can be used to secure your sleeping pad to your bag. If you toss and turn a lot during the night, it’s possible for you to roll off your sleeping pad, but with the straps attached, this can be avoided.

Meet the Author!

By the age of 20, Spencer had already tackled some of the most famed mountain ranges in Europe, Asia, and North America. His mission is to help others accomplish their own outdoor-related goals, even within the time constraints of a 9-5 job and a busy life schedule.

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