The Best Backpacking Sleeping Bag Review

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What is the best sleeping bag for backpacking? We set out to find out. Our complete testing has taken place over several years and on trails across the globe. This review has evaluated over 70 sleeping bags over the years, comparing them in a variety of environments and conditions. The bags were tested by avid recreational backpackers, local mountain guides, and National Park Service scientists on extended trips in summer conditions in the backpacking paradise of California's Sierra Nevada mountains and beyond. Warm nights at middle elevations, early summer season snow, and cold nights above twelve-thousand feet tested the bags on quick mountaineering jaunts and on extended backpacking trips on the Sierra High Route and the John Muir trail.

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Test Results and Ratings

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Analysis and Award Winners

Review by:

Review Editor

Last Updated:
November 22, 2015

Best Overall Sleeping Bag

Western Mountaineering Ultralite 20

Editors' Choice Award
Western Mountaineering Ultralite 20
Price:   $485 online
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Western Mountaineering is a small California-based company that manufactures high quality down sleeping bags and garments. The sub-2 pound Western Mountaineering UltraLite is a slightly narrower version of the Western Mountaineering Alpinlite, also featured in this review. The UltraLite is lightweight, if not ultra-light, warm, and highly compressible. It was the bag of choice for us when spanning multiple elevation zones on one trip and when a few extra ounces paid off for its extra warmth. Where the slim-cut Ultralite lacks in comfort and versatility the Alpinlite takes over. The more spacious Alpinlite is better suited for restless sleepers and for broader shoulders. The wider cut can also accommodate more upper body clothing layers if you use this bag in colder conditions later into the fall. With all Western Mountaineering sleeping bags, you can choose from a few different lengths.

Best for Budget-Minded

Kelty Cosmic Down 20

Best Buy Award
Kelty Cosmic Down 20
Price:   Varies from $150 - $160 online
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The affordable, yet reasonably lightweight and compressible Kelty Cosmic Down 20 takes our Best Buy Award. Cold sleepers and backpackers who frequently extend their three-season trips into lower temperatures will want something warmer, but everyone else on a budget should pick up the Cosmic Down 20 and pocket the several hundred dollar savings. This bag is far more durable and compressible than its similarly priced synthetic insulated counterparts. It offers beginning or budget conscious backpackers an exceptional value. If you are backpacking in very warm summer conditions and want to shave a few more ounces, check out the Kelty Cosmic Down 40.

Top Pick for Wet Conditions

Mountain Hardwear Hyperlamina Flame

Top Pick Award
Mountain Hardwear Hyperlamina Flame
Price:   Varies from $234 - $240 online
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The Mountain Hardwear HyperLamina Flame is a flashy looking new synthetic sleeping bag. Although it is currently the only bag using this insulation type in our newest review, we felt that it deserves attention for being a good bag for those who need the security of staying warm in wet environments. The top zipping design is attention grabbing at first, but really wasn't exceptional in the long run.

Top Pick for Light and Fast Backpacking and Mountaineering

Sea to Summit Spark Sp II

Top Pick Award
Sea To Summit Spark Sp II
Price:   $359 online
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If you're on a trip where weight and space are your number one priority, a one pound sleeping bag slips easily into the corner of your pack and won't remind you it's there until you crawl in for a well deserved good night's sleep. The Sea to Summit Spark Sp II is a high quality, super light-weight, traditional mummy style sleeping bag. It is smartly styled with lightweight fabrics, 850+ Ultra Dry Down, and minimal features to keep the weight down. Our testers used this bag mid-summer, on week-long backpacking trips and quick climbing jaunts in the High Sierra at elevations up to 12,000'.

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Analysis and Test Results

The Sleeping Bag: Your Most Important Insulating Layer

Your sleeping bag is the most important insulating layer that is carried on any wilderness excursion. Sleeping bags provide a better warmth-to-weight ratio than anything else in your pack. Investing in a quality sleeping bag that is suited to your needs will help you get a more comfortable night's sleep, save weight and space in your pack, and keep you warm when the temperatures start to drop. Sleeping bags are also the bed of choice for car campers, travelers, and couch surfers. This review focuses primarily on sleeping bags intended for backpacking. A few of the bags proved to be best suited for car camping, and they tagged along on some road trips throughout our testing too.

We updated our existing Backpacking Sleeping Bag review to include new models and styles and compare them to previous award winners. Sleeping bags that have been discontinued by manufacturers are no longer included to make room for the latest and greatest. This review describes our product selection and criteria for evaluation, and also identifies the best performing bags across this broad category.

Choosing the Right Bag

Our review includes budget friendly down sleeping bags, lightweight down sleeping bags, and reliable synthetic sleeping bags. Please refer to our How to Choose the Best Backpacking Sleeping Bag article to help you decide what is important for you to consider before purchasing a new bag.

One of the first questions to consider is: what type of bag will best fit your needs? We've provided a summary of the major types of bags and their advantages/disadvantages below.

Traditional Style Sleeping Bag

This review primarily compares traditional style backpacking sleeping bags with zippers and hoods. These bags prioritize comfort and versatility. After testing nearly 70 models of all types throughout this ongoing review, we've found that traditional style bags— like those tested here— are a good choice for people that want one bag for all types of outdoor activities. The bags compared here were chosen to be good candidates for 3 season use; here defined as being ideal mid-summer in cool mountain environments and capable of stretching the season from spring into fall. In our most recent review we compared models from 8 different manufacturers that weigh between 1 and 3 pounds.

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Two traditional mummy style bags: the Western Mountaineering Alpinlite (red) and Ultralite (blue) in a side by side comparison. See how they are both a tubular, comfortable shape and have hoods. You can see that the roomier Alpinlite leans towards even more comfort than the Ultralite.

Ultralight Sleeping Bags

The average bag in our Ultralight Sleeping Bag Review, which compares hoodless options, weighs only 19 ounces. Models in the ultralight review provide the greatest amount of warmth for the lowest weight. If you're looking for a lightweight bag that will primarily be used for overnight trips where weight is a concern, we highly encourage you to consider one of the models found in the Ultralight Bag Review. None of these models are currently sold at outdoor stores like REI.

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Hoodless ultralight bags, the Flicker (left) and ZPacks (right) side by side. You can really see how narrow the foot of ZPacks bag is.

Camping Sleeping Bags

A third type is the large and luxurious rectangular bag that is too heavy to carry backpacking. These offer much more comfort than any model tested here and cost as little as forty dollars!! We compare these general-purpose bags in the Camping Sleeping Bag Review.

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Rectangular camping bags: from bottom to top, the Country Squire, Dunnock, Grande, and Conquest. These cotton-lined bags are the roomiest and most comfortable... if you can count on staying dry.

Women's Specific Sleeping Bags

Many manufacturers offer sleeping bags which are specifically designed for females. Often these bags will be smaller and shaped differently to more closely match a woman's frame. They also redistribute insulation to different areas as women are known to sleep colder than men. If you are a woman and are looking for a new sleeping bag, check out The Best Women's Sleeping Bag Review to learn more about the merits of buying a women's specific bag.

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The Sierra Designs Women's Backcountry Bed 800 (left) has more room for your arms to move around whereas the Kelty Ignite is a more traditional mummy shape. Like unisex bags, Women's bags come in many styles and configurations.


Carefully consider the most common application of your sleeping bag. Some bags we consider to be very versatile in where and when you use them. Others are best suited for very specific conditions and trip objectives. If on a budget, don't skimp on quality, look for a bag that balances warmth, weight, and versatility. If possible, consider a lower priced sleeping bag for car camping/campground camping and a lightweight bag for backpacking/mountaineering.

Insulation Options

An important factor to consider when purchasing a sleeping bag is what type of insulation material it uses to keep you warm. Backpacking sleeping bags are available with either down or synthetic insulation. The chosen application of the sleeping bag, the environment and season in which you are travelling, your budget and your experience level will help to determine which insulation material is best for your new sleeping bag.


Down sleeping bags have a higher warmth-to-weight ratio, are more compressible, and last longer than their synthetic counterparts. For these reasons they are generally a better choice for backpacking. A majority of the sleeping bags tested for this review use down insulation. The primary downsides to down bags are that they more expensive and they lose loft when wet, meaning a down bag will not keep you warm if soaked.


There is only 1 synthetic insulation sleeping bag in this new review, the Mountain Hardwear Hyper Lamina Flame. Synthetic bags don't lose loft when when wet, so can keep you warm even when wet. They tend to be heavier and bulkier than their down counterparts and it can be difficult to compare synthetic to down bags for that reason. However, they standout in wet conditions and if you are in a situation where you need one, you will be happy to have the heavier, bulkier synthetic bag. Synthetic bags are suggested for use in very wet environments when a wet sleeping bag is a serious hazard, and for novices who may not have developed the skills or tricks to keep their gear dry.

Care of The Sleeping Bag

Proper care is essential for prolonging the life of your sleeping bag and maintaining its loft and warmth. Keeping down bags dry is imperative for them to function as an insulating layer at all. See our Best Sleeping Bag Stuff Sacks review for suggestions on in-the-field storage options. Storing your sleeping bag at home in a large, breathable storage bag where the down is not fully compressed will maintain loft in the long run. Washing down bags with a very mild soap designed for washing down garments and sleeping bags is important. Western mountaineering has a great page found here that is dedicated to ongoing care of down sleeping bags and garments.

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Storing your sleeping bag regardless of insulation type uncompressed and completely dried out will maintain your bags insulting qualities longer and exponentially extend the life of your bag. Here the Western Mountaineering large (and bright!) breathable storage bag.

Synthetic sleeping bags take less maintenance in the short term. They can get more wet and remain warm, and are generally less fragile than their lightweight down counterparts. They are also are less stressful to wash as the insulation tends not to clump when wet and can be dried easily. However, the nature of synthetic insulation fibers leads them to deteriorate more quickly than down. It is imperative to compress these bags as little as possible over time. The more the fibers get squeezed and then allowed to expand, the faster they lose their insulative qualities. For this reason, a high quality down sleeping bag is a better investment in the long run. Down bags can be compressed over and over and with a few minutes to stretch, the down will return to its lofty self for years to come.

Criteria For Evaluation

We rated each bag on its warmth, weight, packed size, features, and versatility. Our criteria for evaluation for ultralight bags is similar, but with different weighting, so that you can compare performance across reviews.


The amount of loft in a bag, measured as the thickness of the insulation between you and the external environment, has the greatest influence on warmth. Fit is the next most important factor in determining warmth. Bags that are too tight or too short won't allow the insulation to loft properly. Similarly, a bag that's too large will have drafty dead air spaces that make the bag thermally inefficient even though it may have enough loft for the conditions. The crux in selecting a fixed girth model is choosing one that best fits your body and the clothing you plan to wear. Some bags tested here, such as the Western Mountaineering Highlite and the Sea to Summit Spark Sp II have slim cuts that can't accommodate lots of clothing or people with broad shoulders. Western Mountaineering sleeping bags are available in multiple lengths and widths, which is a huge advantage because you can get a bag that fits your body well. Look at the foot, hip, and shoulder circumference to compare dimensions for unisex bags. We've included these measurements in the specification tables found in each review when available from the manufacturers.

The backpacking sleeping bags that we found to be the warmest were the high quality down bags from Western Mountaineering, the Alpinlite and the Ultralite. Both of these bags have 850+ fill power down and plenty of it, 19 and 16 ounces respectively. (The Alpinlite is roomier than the Ultralite, which accounts for the extra insulation.) Both also have draft collars to keep warm air inside the sleeping bag where it belongs. The least warm bag, the lightweight Western Mountaineering Highlite, has only 8 ounces of down and no draft collar. The thinner insulation offers less protection from the elements and the lack of a draft tube allows more cold air inside the bag, leaving the sleeper less toasty than in the other bags.

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The Spark III in the lightweight Black Diamond Betalight shelter on a trans-Sierra backpacking trip. The longer the trip the more important weight and packed size becomes.

Warmth is also heavily influenced by conductive heat loss to the ground. Choosing an appropriate sleeping pad is important, especially in colder conditions or when sleeping on snow. Our Best Sleeping Pad Review will point you in the right direction for a warm, comfortable pad. Choosing the right backpacking tent or ultralight shelter for your trip will influence the perceived warmth of a sleeping bag also. OutdoorGearLab also has an excellent Backpacking Tent Review and Ultralight Backpacking Shelter Review where you can finish out your research on the best sleeping/shelter kit for your next trip.

The new sleeping bags in the review were tested in single wall tents, under tarps and mids, and under the open sky during open bivies above tree-line. See the Buying Advice on how standardized testing has helped (or hurt!) companies decide what temperature rating to give a sleeping bag.


Weight is a function of fill material and amount, shell material, and features. In general, heavier bags use either synthetic insulation or low fill-power down (500-700). Many of the highest performance bags tested here use the best down (850-900 fill-power) and very lightweight, expensive fabrics. However, the primary factor that makes one bag lighter than another is its cut, as described above, and its features, or lack thereof.

The 50-ounce The North Face Furnace is the heaviest down bag tested here at 50 ounces. This exceeds the weight of our lone tested synthetic insulated bag and barely makes the cut to be considered a backpacking sleeping bag in our eyes. The synthetic Mountain Hardwear Flame weighs 43 ounces. Note that all the other bags in this category come in at under three pounds. Heavier bags, which are more comfortable but not suitable for backpacking, are found in the Camping Sleeping Bag Review.

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Weighing sleeping bags for our OutdoorGearLab best backpacking sleeping bag test. There was a pretty big range in weights with some options weighing half of what other models.

At a touch over 16 ounces the minimal Western Mountaineering Highlite is the lightest down bag we tested. In a close contest, the Sea to Summit Spark Sp II weighs 18 ounces in a size Long and scored better overall than the Highlite. The Marmot Plasma 30 is also a top scorer for weight. We would rather carry and use the slightly heavier but more comfortable Spark. Although a one pound bag is impressive to look at and a pleasure to carry, we've found that adding several more ounces of down greatly increases warmth, which, in turn, increases versatility. For lightweight summer backpacking use, where bags around one pound are primarily used, some of our testers prefer a lightweight hoodless bag, like those found in the ultralight sleeping bag review. However, if you prefer a traditional style (zipper, hood etc.) and want to save weight, these bags are excellent for light and fast trips into the mountains where weight and space matter.


Comfort inside of a bag is highly subjective and primarily depends on fit. Increasing the size of the bag provides more space to sprawl about and move within a bag. Take for example the Western Mountaineering Alpinlite and the Western Mountaineering Ultralite, which we compared side-by-side. These bags are almost the same except that the Alpinlite has a wider cut. The wider cut of the Alpinlite is indeed more comfortable. The Sierra Designs Backcountry Bed addresses a long term comfort concern for stomach sleepers looking for a three season sleeping bag by combining attributes of a traditional style mummy bag with the freedom of movement of a quilt, like those found in the Ultralight Sleeping Bag Review.

In addition to space for sprawling and thrashing, our ratings here focus on a bag's features that contribute to or detract from comfort. In this regard we've found that the hood and neck baffle design are most important. We rated the Western Mountaineering Alpinlite and Ultralight much higher than the Highlite largely because they have neck baffles and the Highlife does not.

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1/2 length top zip design on the Mountain Hardwear HyperLamina Flame. The velcro closures on the draft tube and passive draft collar are visible in the photo.

Insulation type influences comfort; sleeping in a down bag is like floating on a superlight cloud while zipping into a synthetic bag is less heavenly.

We also thought it was important to consider total comfort throughout the course of a trip, not just when you're inside your sleeping bag at night. A bag that's slightly more comfortable to sleep in may be heavier and bulkier, and therefore less comfortable to carry. If you spend more time carrying the bag than you do inside of it, we suggest prioritizing weight and bulk (comfort while in your pack) over comfort while sleeping.


Here we assessed the quality of each bag's features and attempted to quantify how well they contribute to the overall performance of the bag. This variable encompasses shell fabric, zippers, draft tubes, neck baffles, and stash pockets. Traditional bags with snag-free zippers, easy-to-use hood adjustments, and hoods that don't come undone at night scored higher in this category, such as the Marmot Plasma 30 and the Ultralite and Alpinlite.

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The Marmot Plasma 30 has one of the most comfortable hoods in our backpacking sleeping bag review.

In most cases, more features or more complicated features reduce performance. They add weight, complexity, cost, and might fail faster. The potential benefit a given feature has on warmth, comfort, or convenience is rarely offset by its drawbacks. For example, stash pockets on sleeping bags. It can be helpful to keep your watch with an alarm in the pocket, but it can be hard to hear the alarm through the down and if you roll in your sleep, waking up on your watch isn't exactly comfortable. In general, when it comes to features, smart design scored well and generally less is more.


Three-season models are meant to be used in a wide range of conditions. They must function on warm summer nights at the middle elevations as well as when the temperatures drop below freezing near treeline in the fall. Versatility across environments, elevations, and seasons is an important consideration when assessing a bag's performance and value. Some of the bags tested here, such as the Western Mountaineering Ultralight and Alpinlite have continuous horizontal baffles that allow you to shift down from the top to the bottom of the bag, which increases comfort in warm conditions and warmth in cold conditions. We find these lightweight bags to be the most versatile in our test. The Sierra Designs Backcountry Bed has no zipper to roll onto and incorporates a quilt that enables you to sleep more like you would with a comforter at home. The quilt can be tucked into the bag when temperatures near the bag's comfort limit and is left outside the bag for warm nights and sleeping on your stomach.

Packed Size

Packed size is a function of down fill power, fabrics, and features. Higher quality down, light fabrics, and simple features create the most compressible bags. Of the models compared here we found The North Face Furnace to be least compressible and the Sea to Summit Spark and Western Mountaineering HighLite to be the most compressible.

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The Mountain Hardwear Hyperlamina Flame vs. Western Mountaineering HighLite in a side by side compression comparison.

Important Accessories

A waterproof stuff sack is critical for keeping your bag dry. Unfortunately, very few bags come with decent quality stuff sacks and many bags come with downright terrible stuff sacks. Thus, we highly recommend purchasing one separately. See our Best Sleeping Bag Stuff Sack Article for our recommendations for specific applications.


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The longer and more ambitious your backpacking objective is the more important spending a little extra to buy a lighter wight sleeping bag becomes. Here two lightweight backpacking bags out for a side-by-side comparison along the John Muir Trail.

The sleeping bag market is a big one, and it can certainly be difficult to narrow your choices down to just one. The balance between warmth, weight, and price is one that is unique to every backpacker. We hope that this review can help you find the product that best fits your backpacking needs, to keep you warm and cozy on nights in the wilderness. For more information on how to select the best sleeping bag, be sure to have a look at our Buying Advice article.

'Dream' Setups

Make sure to also check out our Dream Backpacking Gear list and our Backcountry Trip Planning guide. If you find those helpful, you might also consider reading our Introduction to Layered Clothing Systems.
Mike Phillips
Helpful Buying Tips
How to Choose the Best Backpacking Sleeping Bag - Click for details
 How to Choose the Best Backpacking Sleeping Bag

by Mike Phillips and Max Neale