The Definitive Buyers guide: How to Choose a Sleeping Bag

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If you’re going camping for a weekend holiday, though you have a sleeping bag, you’re probably not overly concerned about how much it weighs or the type of insulation it is. As long as it’s keeping you cosy and warm during the summer nights, it’s a good sleeping bag. But if you’re backpacking, then you’re automatically more concerned about the gear you’re taking with you.

sleeping-nag-with-tent

Of course, you want high-quality gear but there are also other factors which you need to look at before purchasing a sleeping bag. Despite going backpacking in the summer, they’ll be nights where you may be at a higher elevation or in the backcountry, in other words, it’ll get chilly.

With car-camping sleeping bags, they serve a different purpose. Whereas backpacking sleeping bags are designed to be lightweight and compactable. In this guide, we’re going to show you everything you need to know about choosing the right sleeping bag.

When you’re choosing a backpacking sleeping bag, there are four main factors that you’ll need to look at prior to making a decision:

  • Type of insulation: You have three options when it comes to insulation: down, synthetic, or a blend. Naturally, each type of insulation has its pros and cons.
  • Weight vs. comfort: When you’re backpacking, your main concern is weight since you’re carrying everything on your back. Though in many cases, lightweight will mean you’ll have to sacrifice space.
  • Temperature rating: You need to have an idea of the environment that you’re going to be typically camping in. Backpacking sleeping bags come with temperature ranges so that you’re properly protected.
  • Features: There are extra features such as hood styles and draft collars which can make a huge difference when you have to tuck in for bed.

Type of Insulation

sleeping bag insulation

You may be thinking that insulation works to provide you warmth while in your sleeping bag, however, that’s incorrect. Insulation is designed to help reduce your body heat leaving the sleeping bag. For backpacking sleeping bags, you have three options: down, synthetic, and a blend.

Down Insulation

Down is well-known to be an exceptional insulator as it’s made from either goose or duck feathers. If you have a duvet at home on your bed, most likely it’s made with down. The thing about down is that it’s lightweight, compressible, breathable and long-lasting. When it’s cold outside, you’ll be guaranteed to be kept warm and toasty. Essentially, it’s everything you need as a backpacker.

It’s usually more expensive than a synthetic sleeping bag since it outlives them, thus, the price of one will pay itself off in the long-run. The down is measured by fill power which defines the down’s ability to trap heat. This is calculated in cubic inches, thus, it goes by 1 ounce of down in a cubic inch. If the sleeping bag is of higher quality, it’ll use high-quality down which comes from mature birds, thus, able to take a higher temperature rating. For example, a 700-fill power sleeping bag is lighter than a 500-fill power sleeping bag.

You may be wondering if there’s a difference between goose or duck down and the answer is yes. Though many of us thought that goose was the down that’s been typically used, duck has actually replaced goose and is now the most commonly fill used for down. This is simply because more ducks are eaten than geese and down is actually a by-product of the meat industry. This allows the price of duck fill to decrease, thus, providing you with cheaper down sleeping bags.

Many companies are focusing on providing customers with the ethical information behind their duck or goose sleeping bags. Some will even provide customers with traceable information so you know exactly where your sleeping bag is coming from.

Are there any cons to down? Yes, there are. If down becomes wet, your sleeping bag no longer protects and provides you warmth. Instead, it loses the ability to trap heat. However, you need to make sure, if you are purchasing a down sleeping bag that it’s water-resistant. It’ll dry the down out faster. But do keep in mind, even if treated, if your down sleeping bag is exposed to extreme water, it will get wet.

Jen has a good write up on sleeping bag insulation here.

Synthetic

Synthetic insulation is usually made from a type of polyester and is typically less expensive than down. In addition, if it gets wet, it’s able to dry much faster and still provide you with insulation when wet.

Synthetic is also ideal for those suffering from allergies as it’s not made of feathers. Synthetic is usually the best option if you’re going to be camping offseason or in rain-prone environments. Plus, if you’re on a budget, a synthetic sleeping bag won’t break the bank.

Though there are downsides to a synthetic sleeping bag. It doesn’t offer as much warmth as a down sleeping bag does when you compare its weight. In addition, it’s usually a tad larger when packed down and the insulation does reduce over time.

Blend

You can always opt for the best of both worlds and get yourself a down/synthetic combination sleeping bag. These sleeping bags are a hybrid of the two and focus on blending them together to give you the benefits of both insulators.

So which type of insulation is the best one for you?

Choose a Down bag if: you’re looking for extra warmth, portability and durability. Down sleeping bags are typically more expensive, however, they’re long-lasting and have a better value over long-term use. Though, if you’re camping in damp climates, then you may want to avoid using a down sleeping bag unless it’s water-resistant.

Choose a synthetic bag if: you want a budget-friendly sleeping bag that’ll keep you warm. They usually offer good compressibility and retain their loftiness. They’re also very durable and are ideal if you’re camping in damper climates which are prone to rain.

Weight vs. Comfort

carrying mat

For most backpacking sleeping bags, their lightweight and portability come with a bit of a sacrifice. Most sleeping bags, in general, are mummy-shaped, though you’re able to find some that are semi-rectangular or peanut-shaped as well. These styles are all usable for backpacking, however, some will offer different levels of comfort and weight than others.

Shape and Fit

If you’re looking for your sleeping bag to be lightweight and warm, then you’ll want to opt for a mummy-shaped bag which has a narrow shoulder/hip size. This will work to keep you properly insulated, however, the mummy-style shape is found to be slightly restricted as you cannot move around in it as much.

Now, if you’re wanting a sleeping bag that provides you with more comfort and weight, you have a couple options. You can choose a mummy-style bag that has wider shoulder/hip sizes or you can choose a semi-rectangular sleeping bag which is ideal for those with a broad frame or who prefer more space when sleeping. Though, you will have to deal with a heavier sleeping bag if you choose the latter.

The shape and fit of your sleeping bag effects the comfort level and the restfulness you receive throughout the night. Naturally, as stated above, though most sleeping bags are designed in a mummy-shaped style, you do have the option of going for a semi-rectangular or peanut-shaped bag.

What you need to know about Heat Loss

It’s important to know how not only the construction of a sleeping bag but how a sleeping bag can lose its heat. That way, you can safeguard against it and keep as much heat inside your bag as possible. The reason why sleeping bags keep you warm is that they trap and hold “dead” air around your body.

Dead air is simply non-circulating air. So, the dead air works by being warmed by your body heat. The sleeping bag functions as a barrier from the outside, making sure that the cold or outside air doesn’t come in the sleeping bag.

There are four factors which contribute to heat loss:

  • Conductive heat loss: is when objects varying in different temperatures are in contact with one another. For example, as a backpacker, this refers to your body’s contact with the cold ground. In order to prevent conductive heat loss, the best line of defence is an insulating foam sleeping pad as it raises you up from the ground and acts as a barrier.
  • Radiant heat loss: is when heat dissipates from the body. Though the amount of heat loss depends on the temperature difference between two surfaces. For example, the two surfaces can be your skin and the sleeping bags inner lining. The heat then travels through the air and is absorbed by small fibres and white fill.
  • Convective heat loss: is usually the most common source of heat loss when you’re in your sleeping bag. Convective heat loss is the loss of heat through air currents. Manufacturers minimize this form of heat loss by using insulation strands to block the air from trying to escape your sleeping bag. The insulation strands are usually tangled using large diameter fibres to block this from happening.
  • Evaporative heat loss: is the loss of heat caused when moisture transforms from liquid to vapor. You have probably felt this yourself when you feel your wet skin cooling – this is what happens during evaporation. When this happens you should change your clothes if they’re sweaty or damp into something dry prior to getting into your sleeping bag. Even though you may not think your damp clothes make a difference, they do.

Sleeping bag Construction

sleeping bag construction

The way the sleeping bag is constructed will give you a better idea how it insulates heat, keeping you warm and cosy at night. A sleeping bag has an outer shell and an inner lining, though, there are several techniques which hold the insulation in place.

Down sleeping bags use a baffling method while synthetic bags use a shingle or layered method for insulation. Whichever insulation method is used, the purpose is to avoid the cold spots as much as possible for an evenly insulated sleeping bag.

Down sleeping bags:

Like stated previously, down sleeping bags typically use a baffle method in order to insulate the sleeping bags. There are two types of baffle constructions:

  • Box: The box baffles approach is very strong and works to keep the down from shifting around in your sleeping bag. This is usually the most common issue and prevents proper insulation around the entire bag for consistent warmth. These box baffles can be designed as slant or trapezoid boxes which are used most often in the footbox area of the sleeping bag.
  • Sewn-through: This approach is typically used in ultra-lightweight sleeping bags as it requires less insulation per baffle. Though, there is a downside to this approach as it’s more common for cold spots to occur in the stitched areas.

Synthetic sleeping bags:

For synthetic sleeping bags there are also two different approaches used:

  • Shingles: Shingles are pieces of cut sheets or fill are then stitched to the shell and lining. They overlap each other, mimicking the shingles on a house.
  • Layered: This is usually the most popular method for synthetic sleeping bags. The off-set quilt method is 2 layers of insulation which prevents cold air from getting in between the seams. The top layer of insulation is sewn to the shell and the bottom layer of insulation is sewn to the lining. It’s a very simple method, yet, highly effective. Then, the shell, lining, and insulation are all sewn together with a single stitch. This is typically more cost-effective and used on warmer sleeping bags.

Sleeping Bag Shell and Lining

Another important feature of the sleeping bag is the shell and lining. Typically, the outer shell of the sleeping bag is made of ripstop nylon or polyester as they’re highly durable materials. Usually, when looking for a backpacking sleeping bag, you’ll want the outer shell to be durable enough to prevent snagging or tearing.

Any high-quality sleeping bag, regardless of the material used for the outer shell, will have a water repellent coating finish. Durable water repellent (DWR) is an extra barrier that will prevent the water from soaking into the bag. Instead, it’ll force the water to slide off the bag instead of being absorbed.

The inner lining of the sleeping bag is usually designed to remove any moisture, thus, there will be no DWR used on the lining. If you want to know if your sleeping bag has a DWR finish, place some water on the bag. If the water beads, then it has a DWR finish.

Sleeping Bag Length

Most adults sleep in either a Regular or Long sleeping bag, though, this depends on your heights. If you’re petite, there are some bags available which are labelled as Short. If you’re tall, you can opt for an X-Long sleeping bag.

Each size depends on the producer and gender. The best way to figure out the height of a sleeping bag is to look at the manufacturer’s specs as it’ll list the maximum height for the sleeping bag. It’s important to make sure the sleeping bag properly fit you, if you end up with a sleeping bag that’s too long, the heat will escape in the footbox, leaving you with cold toes.

Here’s a standard guide for the length of a sleeping bag:

Men’sWomen’s
Short: For men up to 5’6” Regular: For women up to 5’6”
Regular: For men between 5’7” to 6’0” Long: For women between 5’7” to 6’0”
Long: For men between 6’1” to 6’6”

Women-specific sleeping bags

Over the past years, the demand for female sleeping bags has dramatically increased. These bags are different than your general sleeping bag as it’s designed to fit the contours of the female body. If you compare a female sleeping bag to a men’s bag, you’ll find that the female sleeping bag has these general characteristics:

  • Possibly extra insulation in the upper body or footbox
  • Wider specs in the hip area
  • Narrower specs at the shoulders
  • Shorter in length

Though, if you’re a petite woman, you may also find that youth sleeping bags are more comfortable and fitting for you. But, one downside is that they may not have the features which adult sleeping bags have.

Temperature Rating

sleeping bag by river

When camping, though it may have been a warm summer’s day, the minute night comes, it’s a different story. The nights can become chilly and windy, thus, you’re going to need to be kept warm. Of course, there are a couple factors which you need to think about that also affects the warmth of your sleeping bag.

Tent: If you’re sleeping with a tent, it’ll act as another layer of protection, trapping dead air. With a tent, it can warm up the sleeping place.

Metabolism: Your metabolism has a huge effect on how you sleep. If you’re someone who’s always cold when sleeping, then you’re going to need extra insulation. If you’re someone who’s always warm, you’re most likely not going to need a heavy-duty sleeping bag.

Clothing: The clothing that you wear to sleep also influences your overall warmth. To increase insulation, opt for wear long underwear and clean socks as this will keep you insulated. If you’re a “cold sleeper” then a cap and neck gaiter can also help keep you warm.

Gender: Interestingly, gender does have an influence when choosing a sleeping bag. Typically, women prefer to sleep in slightly warmer sleeping bags than men.

Sleeping Pad: A sleeping pad works by bringing your body off of direct contact with the ground, automatically providing you more warmth. In addition, it also aids to give you extra cushioning.

These factors all contribute to how you’ll sleep at night in a sleeping bag. Though, there are some loose guidelines you can follow that’ll help you decide what temperature rating you need for your sleeping bag.

Type of Sleeping BagTemperature Rating (Fahrenheit)
Winter/Extreme+10° and lower
Summer Season+32° and higher
3-Season+10° to +32°

Following this guide will provide you with a general idea of what each type of sleeping bag can provide you. Though, you may be wondering how they come up with this temperature rating. Well, in order to rate each sleeping bag, it undergoes an “EN test”.

The EN test is short for the European Norm 13537 testing method. It started in 2009 for sleeping bag producers to have a reliable temperature rating for their 3-season sleeping bags. Sleeping bags are laid on top of an insulating pad in a climate-controlled chamber.

A mannequin which simulates the average human body temperature is placed in the chamber and measurements are taken off of the surface of the mannequin. With these measurements, a temperature rating is produced.

The EN test has two objectives:

Comfort ratings: lowest outside air temperature at which a standard woman can sleep comfortably in.

Lower-limit ratings: lowest outside air temperature at which a standard man can sleep comfortably in.

Though, it’s important to understand that the test is based on the sleeper wearing a minimum base layer and hat. Take the EN ratings has a general guideline as everyone is different. If the sleeping bag you’re interested in isn’t rated with the EN test, then select the bag with a slightly lower temperature rating.

Features

Though these are necessarily necessities, there are features which can dramatically increase your warmth and comfort while in your sleeping bag. Of course, you should always focus first on the temperature rating, and type of sleeping bag you want first.

Once you’ve decided if you want down or synthetic, a 3-season or summer sleeping bag, then you can focus on the features. There are hundreds of different sleeping bags available, so, focus the features you want to help narrow down your options.

Draft Collar

The draft collar, also known as neck baffles are usually designed for sleeping bags that are meant to be used during colder weather. You typically won’t find this feature on a summer bag. Draft collars are insulated baffles that are around your neck and head to prevent body heat from escaping and any cold air from creeping in. This is an important feature for winterized sleeping bags.

Hood

Without a hood, you’re leaving yourself open to losing heat. When a hood is completely cinched, it prevents heat from dissipating. There are hoods available which offer a pillow pocket where you can place clothing inside to create a make-shift pillow. There are also some hoods which are designed to lay perfectly flat when the bag is unzipped. For ultra-lightweight sleeping bags, they may have completely ditched the hood to save weight. Though, you may be able to find some ultra lightweight sleeping bags with a hood as well.

Draft Tube

A draft tube is an insulation-filled tub which runs along the inside of the main zipper. Its purpose is to keep the warmth from escaping through the zipper coils. Though it’s a small feature, it’s extremely handy and you’ll notice a huge difference when the air actually stays inside your bag.

Stash pockets

When you’re in your sleeping bag you may feel more comfortable keeping your valuables close to you such as keys, ID, or money. Stash pockets allow you to do just that. The small pockets inside your sleeping bag that let you store small items. There’s no set location for the pockets and vary on the manufacturer.

Trapezoid Footbox

The trapezoidal footbox is designed to provide you with more space in the foot area. Many people complain about sleeping bags not allowing them to sleep in natural positions. Well, the footbox allows you to sleep in your normal sleeping position by reducing tension around your feet. This also helps in increasing the longevity of the insulation around the feet.

Pad Sleeves

There are some sleeping bags which remove insulation on the bottom and replace it with a sleeve or attachment for a sleeping pad. What this does is reduce the pack weight of the sleeping bag and allows it to compress itself into a smaller size. It’s a great feature to look for if you’re concerned about the space inside your backpack.

Differentiated cords

Differentiated cords are a small feature, yet, make a huge difference when you’re in the dark. The difference in shape and size to allow you to tell which cords do what. It makes it much easier to operate your sleeping bag from inside.

Pad loops

Pad loops are sewn-in strap which allows you to secure your sleeping pad directly to your bag. Many campers complain about their sleeping bag sliding off of the pad in the middle of the night, causing a disrupted sleep. Pad loops give you a secure grasp to your pad while you’re sleeping at night. Pad loops can also be used to hang your sleeping bag away for storage.

Zipper Compatibility

Though you may not think about it, zippers are a major concern when looking for a sleeping bag. You want a zipper that’ll be durable and long-lasting. There are some backpacking sleeping bags that are designed to allow other sleeping bags to be zipped together. Thus, you can connect two sleeping bags together for either more space or if you’re sleeping with another person. Though, by merging two sleeping bags together, it’s important to know that it does create a gap which allows heat to escape. If you’re wondering how to tell if two sleeping bags can mate, look for these factors:

  • The zippers are the same size. It’s typical for more companies to use either a #5 or #8 size zipper. You need to make sure that the two zippers match.
  • One of the sleeping bags has a right-hand zipper and the other one has a left-hand zipper.
  • The length of the zippers match. Some sleeping bags will come with ¾ length zippers while others are ½ length zippers. Of course, you can zip together two sleeping bags of different lengths, but there may be cold spots which won’t be able to be covered.
  • You can zip together two sleeping bags which have different temperature ratings as well, this doesn’t affect the mating of two bags.

Sleeping Bag Liners

This accessory is sold separately from the sleeping bag and is typically used to keep your sleeping bag clean. A sleeping bag liner is typically used for mummy-style sleeping bags. If you have a rectangular sleeping bag then you’re going to look for “travel sheets” – they’re the same thing just named differently.

A bag liner not only makes sure your sleeping bag is clean but it also can add some extra heat to your sleeping bag, approximately 5° to 15°F of extra heat, depending on the liner material. In hot climates, you can even use the liner on its own without the sleeping bag. You usually have a couple different liner materials to choose from:

  • Silk: This is a very lightweight material which is used to help insulate from cold weather. At the same time, it’s also highly absorbent and breathable and can also be used during warm weather as well. Though it can be expensive as it is silk.
  • Fleece or microfleece: If you’re in damp or colder climates, then you’ll want to opt for fleece. Though they’re a heavier fabric, they’re much warmer. Fleece is also very soft, moisture-wicking, and fast drying. But if you choose a mid or heavyweight fleece, it’ll be bulky.
  • Cotton: It’s a natural, highly-breathable fabric that’ll last you years. The only downfall is that it’s not the lightest material or portable. Plus, when it gets wet, it becomes even heavier. It is more affordable in price, though, not ideal for damp climates.
  • Synthetics: Materials such as CoolMax or MTS are moisture-wicking and highly breathable. These materials are ideal for humid conditions. They’re affordable in price and also come with a little bit of stretch in them as well.
  • Insulated: Insulated materials will provide you with extra warmth as they’re designed with hollow-core fibres. If you’re in damp conditions, they dry up 50% faster than cotton. Though, they’re not as affordable as cotton or synthetics.

Choosing a sleeping bag isn’t as easy as you first thought. There are a lot of factors to take into consideration. If you’re car camping, then maybe you don’t need to spend as much time choosing a sleeping bag. However, as a backpacker, you’re aware that the only tools and support you have with you are in your backpack. With that being said, you need to be properly prepared to face the elements. Take your time when looking for a sleeping bag.

Think about when you’re considering going camping and how many seasons you’ll be using this sleeping bag. Research the areas you’re going to be backpacking in and look at the climate you’ll be facing. From there, you’ll have a better idea of what type of sleeping bag you’ll need. Once you have the base of your sleeping bag figured out, then you can focus on features that you feel you’ll need during your trip.

Though you may want to save some money here and there, try not to cheap out on your sleeping bag. A good night’s sleep is extremely important when you’re backpacking, as it’ll set the mood for the entire day. Not only that, you need to be in your best physical shape on your trip. If you have a sore neck or back, you’ll feel it in the morning and that’s exactly what you don’t need.

If you’re someone who is prone to neck or back pain, make sure you bring a pillow and sleeping pad with you to eliminate any discomfort. Though this may seem like extra weight, it’s extra weight that you need to bring along with you.

Backpacking is a lot of fun when you’re properly prepared. You want the trip to be one that you have positive memories of and not one that you remember because you shouldn’t move your neck in the morning. So, follow this guide when looking for a sleeping back and you’ll find the right one for you.


Ready to get a sleeping bag that is perfect for you? I have narrowed down a list of good ones. Check out my guide to the Best Compact Sleeping Bags.

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