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You can't put a price on a great night's sleep. Staying warm and comfortable in the backcountry is not just an important safety precaution; it helps you enjoy the outdoors to the fullest. Choosing a sleeping bag that balances warmth with weight is key for backpacking.
Our favorite overall backpacking sleeping bag is the Western Mountaineering MegaLite. This USA-made bag is toasty and one of the lightest-weight bags in our lineup, but you'll be paying top price for top performance.
If you're looking for something a bit more budget-friendly, the Exped Terra 15 may weigh a few more ounces than the Megalite, but it's actually a warmer sleeping bag that still weighs less than 3 pounds.
We've been hitting the trails to test sleeping bags since 2011 and have now rigorously tested upwards of 100 top models. For this review, we purchased 17 of the best sleeping bags on the market and tested them side by side, ranking them based on their overall performance and value. From the snowy peaks of the Sierra Nevada to the sweltering deserts of Death Valley, our team of experts has spent countless nights considering every aspect of these bags. You care about your gear choices – we've done the legwork to make it easy to select a great sleeping bag.
Editor's Note: We updated our backpacking sleeping bag review on May 17, 2026, to add new bags from REI, Sea to Summit, Exped, Marmot, and Enlightened Equipment.
Like other ultra-premium down sleeping bags, the Western Mountaineering MegaLite offers maximum warmth with minimal weight in a bag that effortlessly packs down to 6.6 liters. But unlike other ultra-premium down bags we tested, it features a spacious interior that provides superior comfort, whether you sleep on your front, back, or side. “I'm a lifelong side sleeper, and I found plenty of room to roll over in this bag,” our lead tester Ian McEleney said. If you don't need quite as much warmth but weight and packed size are priorities, consider the more snug-fitting Feathered Friends Hummingbird 30, which we measured to be about 1.3 pounds lighter and 1.1 liters smaller than the Megalite.
SPECIFICATIONS
Temperature Lower Limit Rating
22°F (manufacturer rated)
Comfort Rating
Not Available
Insulation
Goose down, ethically sourced
Packed Volume
6.6 L
Measured Weight (Size Regular)
1.5 lbs
Our gripes about the Western Mountaineering MegaLite are few and minor: the hood closure is a bit awkward, and it's not super comfortable when cinched tight. More notably, this bag is just plain expensive. If you really want to prioritize weight and space savings, the MegaLite or Hummingbird is where it's at, but the less expensive Exped Terra 15 goes toe-to-toe with them in terms of warmth and overall comfort. Still, we think the MegaLite is worth the investment for serious backpackers trekking in cold climates, especially given that this rugged bag has lasted us for many years. “This is the bag for the backpacker who wants everything and doesn't mind paying for it,” one of our testers notes. “If you've got the budget, I wouldn't hesitate to recommend the Megalite.”
Down insulation bags can get really pricey, really quickly. Fortunately, the Exped Terra 15 is an exception to that rule. It's stuffed with a good amount of duck down for superior insulation over a synthetic sleeping bag like the REI Trailmade 25. While the insulation quality isn't as high-quality as the Western Mountaineering Megalite, there's plenty of it to go around, and this bag has some standout features that boost warmth and comfort. A thick draft tube fully insulates you from air seeping through the zipper. The large draft collar and plush hood each have their own drawcord, so you can cinch them down tightly to create a snug cocoon. A large, easily accessible interior pocket keeps essentials like a phone or headlamp close at hand, while a glow-in-the-dark, anti-snag zipper makes it easier to get in and out of your bag in the middle of the night. Tester Arthur McMahon said, “Given how affordable this bag is, it's incredible how many features they packed in that genuinely help make camping more comfortable.”
SPECIFICATIONS
Temperature Lower Limit Rating
12°F (ISO)
Comfort Rating
25°F (ISO)
Insulation
European Grey Duck Down, RDS certified
Packed Volume
9.0 L
Measured Weight (Size Regular)
2.8 lbs
The Terra 15 does have some limitations, especially compared to some of the more premium bags we tested. Even though it still weighs less than 3 pounds, it's a far cry from the ultralight bags that are becoming increasingly popular. The mid-tier down insulation (650+ fill power) doesn't compress as well as more premium down (800+ fill power), resulting in a 9-liter package that takes up about as much space as a basketball. We really do like the robust compression sack it comes with, though, which reduces it to as small a package as possible. If you can afford spending a bit more, the REI Co-op Magma 15 is a little smaller and lighter, but the Exped Terra 15 is certainly the more budget-friendly option. All that said, most backpackers will find a lot to love about this sleeping bag. The warmth, comfort, and features are worth their weight in down, and we'd happily carry the Terra 15 on any backpacking trip.
Outdoor gear is increasingly expensive, and we rarely see any essential items as affordable as the REI Co-op Trailmade 25. Though this sleeping bag may be among the least expensive on the market, it's not limited in performance, at least among other synthetic bags we tested. One tester noted, “The Trailmade 25 is a great option for anyone going on their first backpacking trip. The price is approachable, and it has everything you need for a few comfortable nights in the backcountry.” Unlike other sleeping bags that sometimes only come in Regular and Short, the Trailmade 25 is available in multiple length and width options, making it much more inclusive. As a synthetic-insulated bag, it'll continue to insulate even when wet, and the shell has a durable water-repellent (DWR) coating to effectively shed condensation.
SPECIFICATIONS
Temperature Lower Limit Rating
20°F (ISO)
Comfort Rating
31°F (ISO)
Insulation
100% recycled polyester
Packed Volume
8.0 L
Measured Weight (Size Regular)
3.0 lbs
Synthetic fill is heavier and compresses much less than down insulation. We tested the Trailmade 25 in Medium, which weighed 3 pounds and packed down to 8 liters. Even though this packed size is directly comparable to the Exped Terra 15, this down sleeping bag is much warmer than the Trailmade – the Terra was quite comfortable well below freezing, whereas we didn't want it to get much colder when the temperature dipped to 32°F while testing the Trailmade 25. To compare similar temperature ratings, the Feathered Friends Hummingbird UL 30 has a similar lower limit rating to the Trailmade, but it weighs just over one pound and packs down to 5.5 liters. While the Hummingbird UL 30 is much more expensive than the Trailmade 25, it's a specialty ultralight bag. The Trailmade 25 may not be as “premium” as many of the other bags we tested, but it is still quite good at what really matters – keeping you warm and well rested.
The REI Trailmade 25 simply works. It may not be flashy or feather-light, but there's no arguing that it's an incredibly good value. Credit: Arthur McMahon
If you know you “sleep cold” or have plans for colder trips in the spring or fall, the Western Mountaineering UltraLite is certainly worth considering. With 17 ounces of premium down, this bag is easily the warmest one we tested. Our lead tester self-identifies as a cold sleeper, and he used it at 12,000 feet in October without any problems staying warm. At the same time, its full-length zipper lets you quickly shed heat and cool off on warmer nights. He says, “Over a season's worth of testing, I slept quite comfortably in the Ultralite in temperatures ranging from 10° to 55°F.” The more affordable REI Co-op Magma 15 has a similar lower-limit rating to the Ultralite, but it doesn't have the continuous horizontal baffles that keep the insulation from bunching up and offer superior heat retention.
SPECIFICATIONS
Temperature Lower Limit Rating
14°F (manufacturer rated)
Comfort Rating
Not Available
Insulation
Goose down, ethically sourced
Packed Volume
9.0 L
Measured Weight (Size Regular)
1.8 lbs
Unsurprisingly, exceptional performance tends to come at a premium price. Even so, many consumers will appreciate that Western Mountaineering is a small company producing all its bags in the USA. We feel most 3-season hikers can make do with a bag that is less insulated, lighter weight, and packs smaller than the Ultralite – even the similarly expensive Western Mountaineering Megalite is a better option for most people. If warmth is paramount but so is your budget, the similarly sized Exped Terra 15 offers warmth on par with the Ultralite, yet it's less than half the cost. That said, if you're willing to pay top dollar for the best balance of warmth and weight, you can't find a better sleeping bag than the Western Mountaineering Ultralite.
The Feathered Friends Hummingbird UL 30 is our top choice for anyone counting ounces. Feathered Friends uses the highest-fill-power down we tested (950+) to create a really warm and shockingly lightweight bag. Somehow, this bag also features a sturdy full-length zipper that's virtually immune to snagging – a pretty unique feature among minimalist, ultralight sleeping bags. The Hummingbird also unzips so you can use it as a 2-person quilt if you'd like to share and keep your team's weight even more minimal. “Our testers fought over this bag when they wanted to keep their packs as small as possible,” reports lead tester Ian McEleney. “I agree, it's a nearly perfect sleeping bag for moving quickly and covering great distances.”
SPECIFICATIONS
Temperature Lower Limit Rating
30°F (manufacturer rated)
Comfort Rating
Not Available
Insulation
Goose down, RDS-certified
Packed Volume
5.5 L
Measured Weight (Size Regular)
1.3 lbs
The Hummingbird UL 30 achieves its low weight and high warmth with a narrow fit. Side sleepers and anyone larger than the 5'10", 170-pound, relatively average frame of our testers might find the cut of this bag to be pretty restrictive. If you want a roomier fit, we recommend the Western Mountaineering MegaLite. As a specialty ultralight bag, this sleeping bag comes with a matching ultra-high price point. But if you fit within its dimensions and it's within your budget, there are few other bags that offer the warmth-to-weight ratio of the Hummingbird UL 30.
While the Hummingbird UL 30 is our favorite ultralight option compared to your typical sleeping bag, we also have a review dedicated to comparing the best ultralight sleeping bags against one another.
The Hummingbird's supreme loft and smooth-operating, anti-snag zipper are what backpackers' dreams are made of. Credit: Arthur McMahon
Product Comparison Table
Sleeping bags for backpacking prioritize low weight and packed size so you can rest and recover a long way from home. Credit: Jack Cramer
How We Tested
We purchased the most popular backpacking sleeping bags for extensive hands-on testing. We measured warmth, weight, and packed size in the lab. Then we assessed performance metrics, including comfort, versatility, and design, in places like California's spectacular Sierra Nevada, Wyoming's Wind River Range, Zion National Park, and Death Valley National Park. Bags were tested at elevations ranging from 150 feet below sea level to 14,000 feet above sea level, with nighttime lows between 10°F and 70°F.
Sleeping under the stars can be an amazing experience. If you're in a down bag, be wary of rain or heavy dew. Credit: Jack Cramer
This review is also unique in that it directly compares products from Western Mountaineering and Feathered Friends. These specialty manufacturers have a reputation for sourcing some of the best goose-down products on the market, but their reluctance to offer free samples means few of their products appear in reviews. Fortunately, GearLab's policy of purchasing every piece of gear we test gives us the flexibility to include models from both companies in this comprehensive review. And we're glad we did — they're well-made sleeping bags that achieved some of the highest overall scores.
No freebies from marketing teams for us - we purchase everything we test, so our experts are free to scrutinize every sleeping bag. Credit: Arthur McMahon
Our testing of backpacking sleeping bags is divided into five key metrics:
Warmth(25% of total score weighting)
Weight(25% weighting)
Comfort(20% weighting)
Packed Size(15% weighting)
Features(15% weighting)
We slept for hundreds of nights in all kinds of weather to find the bags with the best comfort and utility. Credit: Elizabeth White
Why Trust GearLab
Lead tester Ian McEleney started playing outside in New England, and like many others, over time, he has made his way west. He now lives and guides in the Sierra Nevada as an AMGA-certified alpine guide who has helped over 1,000 clients select the ideal gear for their backpacking, mountaineering, and climbing goals.
And co-author Arthur McMahon is an intrepid explorer who has thru-hiked the Pacific Crest Trail and other famous backpacking routes, including the Teton Crest Trail and the Grand Sawtooth Loop.
They've all spent the better part of the last two decades in the backcountry, developing the expertise to evaluate all sorts of outdoor gear. For this review, they consulted with Appalachian and Pacific Crest Trail thru-hikers, NOLS alumni, manufacturer reps, and novice backpacker friends to ensure a diverse array of perspectives.
We extensively tested these sleeping bags in the field, and closely examined every feature in the lab.
How To Pick The Best Sleeping Bag For You
Ignoring our test results for a moment, consider the following questions to help guide your purchase. The more honest and practical your answers are, the more likely you'll get the best sleeping bag for your needs.
What experience do you want to get from your sleeping bag and backpacking in general? Credit: Arthur McMahon
Choosing the right temperature rating is one of the most important parts of buying a backpacking sleeping bag, and the smartest approach is to shop for the overnight lows you expect to encounter most often. Most sleepers should focus on the bag's comfort rating, as it is generally a more realistic indicator of how comfortably the average person will sleep through the night. The lower-limit rating is better viewed as an emergency benchmark. Keep in mind that factors like your sleeping pad, clothing layers, and whether you sleep warm or cold all affect real-world performance. When in doubt, it's easier to vent a slightly warmer bag than to magically create warmth.
Many sleeping bags labeled for men or women are really designed around average body dimensions and warmth needs rather than strict gender rules. Women's-specific models often have a shorter overall length, narrower shoulders, wider hips, and extra insulation in areas where many sleepers tend to get colder.
Men's or unisex bags may offer broader shoulder room and longer sizing options. The right choice comes down to fit, comfort, and warmth preference — not the label. If one version matches your body shape better, that is usually the smarter buy.
A sleeping bag can only do so much if the pad beneath you isn't doing its job. While the bag traps warm air around your body, the insulation compressed underneath you provides very little protection once your weight flattens it out. That's where a sleeping pad's R-value becomes critical. R-value measures how well a pad resists heat loss into the cold ground, and it often has a bigger impact on overnight warmth than many campers realize. As a general guide, pads rated around 1 to 2 work best for warm summer nights, 3 to 4.5 are solid three-season options, and 5+ models are better suited for late fall, winter, or snow camping. In real use, a lightweight summer pad with an R-value of 2 may feel fine on a 60°F night, but that same pad can make a 30°F trip feel far colder than your sleeping bag's rating suggests. Even a highly rated sleeping bag can underperform when paired with an under-insulated pad, while a quality pad with the right R-value can noticeably improve comfort and help your bag perform closer to its intended temperature range. In colder conditions, choosing the right sleeping pad is not an accessory decision — it's an essential part of your sleep system.
Using a warmer sleeping pad, or using a foam pad and an inflatable pad, can let you take your sleeping bag outside of it's normal range. Credit: Luke Lydiard
Down insulation offers excellent warmth for its weight, packs smaller, and can last for many years with proper care, which is why experienced backpackers often prefer it. The catch is moisture — if a down bag gets wet from rain, condensation, or poor storage and you don't know how to dry it properly, it can lose much of its loft and provide very little warmth until fully dried. Synthetic insulation is typically heavier and bulkier, but it continues to insulate better when damp, dries faster, and requires less careful handling. That makes it a more beginner-friendly and dependable option for first trips, wet climates, or anyone who values reliability over saving space. In short, down is often the premium choice in ideal conditions, while synthetic is frequently the smarter choice when conditions, or experience, are less predictable.
Traditional sleeping bags remain the best choice for many campers because they are simple, warm, and intuitive to use. They include a hood, enclosed footbox, and full wraparound design that helps seal in heat on cold nights. Quilts remove the insulation beneath you, where it gets compressed anyway, and rely on your sleeping pad for bottom insulation, saving significant weight and bulk. The tradeoff is a steeper learning curve and more potential for drafts if not set up properly. For beginners or cold sleepers, a sleeping bag is often the safer choice. For experienced backpackers focused on cutting pack weight, a quilt can be a smart upgrade.
Quilts like the Enlightened Equipment Enigma 20 often cut features and conveniences to save on weight and space. Credit: Arthur McMahon
Not everyone needs the latest, greatest, and lightest bag. It truly depends on your goals, style, and terrain. For some, comfort will be king. For others, weight and pack size will be the driving factor. How far you plan to venture and the terrain are huge variables. If you're only planning to walk a few miles each day, a 3.5 to 4-pound sleeping bag won't make or break your trip, and could save you hundreds of dollars. However, if you plan to gain several thousand feet of elevation or are planning multiple nights, lowering your weight to around 2 pounds will make a real difference in your overall pace, efficiency, and fatigue. For extended trips or those that require extra gear, it is definitely worth investing in an ultralight bag that weighs under 2 pounds. This is all to say: don't feel pressured to get the lightest bag on the market; get the lightest bag you can afford that facilitates your dream trips. If you want to cut your weight even further, you'll likely need a sleeping quilt instead, which can often cut that weight in half.
Your sleeping position can have a major impact on which backpacking sleeping bag feels comfortable through the night. Back sleepers can often take full advantage of traditional mummy bags, since the tapered shape aligns well with a straight sleeping posture and maximizes warmth by reducing extra interior space. Side sleepers, however, often need more space through the shoulders, hips, and knees, since turning or curling up inside a narrow bag can feel restrictive and lead to an iffy night of sleep. Side sleepers will likely prefer roomier mummy cuts, spoon-shaped designs, or quilts that allow easier movement. In practical terms, back sleepers can usually shop by temperature rating and weight first, while side sleepers should pay close attention to fit and interior space, since the warmest bag in the world won't matter much if you can't get comfortable inside it.
The top-scoring Hummingbird UL is a great ultralight sleeping bag, but as a specialty option, it's not necessarily the best bag for everyone. Credit: Jessica Haist
Analysis and Test Results
Good design is a balancing act, and that's certainly true for backpacking sleeping bags. Add enough insulation to make the bag warm enough for every situation, and it can become too heavy. Cut that weight by shortening the zipper, and you reduce the ability to vent excess heat. It's all a game of tradeoffs.
To evaluate today's top sleeping bags, we selected five performance areas that are sometimes at odds with one another: warmth, weight, comfort, packed size, and features. The push and pull between these metrics results in bags that are good for different uses and users. We've accounted for every aspect of performance so you can home in on the ones that matter most to you.
Worse Value
Better Value
What's the Best Value?
Sleeping bags come in a wide range of prices, even though they ostensibly serve the same purpose. After extensive testing, we can confidently say that a bag's price reflects real performance differences. Anyone able to shell out for a high-end sleeping bag – like those from Feathered Friends or Western Mountaineering – will get one that lasts a decade or more if properly cared for. However, there are affordable options that are notable for their balance of price and performance:
Exped Terra 15: For less than half the price of the premium options we tested, this one offers an exceptional value. Although it's a little heavier and bulkier than other premium down sleeping bags, it's just as warm and comfortable.
REI Co-op Trailmade 25: This fared well compared to other sleeping bags with synthetic insulation, and the price simply can't be beat. It will be bulkier than any down sleeping bag, including the Terra 15, but compared to other synthetic bags, it offers the best balance of warmth and weight.
At such an affordable price, the REI Co-op Trailmade 25 is a hard bargain to pass up, especially for first-time backpackers. Credit: Arthur McMahon
Warmth
The warmth of a sleeping bag depends primarily on the quality and quantity of the insulation. Models with down insulation are generally lighter, more packable, and more expensive. They can also keep their loft for a long period if you take good care of them. Bags with synthetic insulation are usually heavier, bulkier, and less expensive. That said, wet down loses all of the insulating properties, and it can take a long time to dry down after a soaking. Synthetic bags will also lose some warmth when wet, but overall, they will keep you warmer than down bags under these circumstances. So, synthetics can be better choices for particularly wet activities (like packrafting) or damp environments.
For down bags, you can make a rough estimate of the warmth by considering the fill power and fill weight. Fill power is a measurement of the “loftiness” of the down fill, corresponding to the amount of air a certain weight of down can trap. More trapped air translates into more trapped body heat. Sleeping bags usually contain down with a fill power between 500 and 900, with higher numbers indicating higher insulating ability. Fill weight is simply the amount of down inside the sleeping bag. Though manufacturers like to boast about fill power more, we think fill weight is much more important. Two sleeping bags with the same fill weight and fill power might not provide identical warmth, but they should be pretty close. However, other design elements (like hood design, zippers, baffles, draft collars, etc.) can also play a role.
The Western Mountaineering MegaLite was plenty warm for our chilly nights out. Credit: Elizabeth White
Estimating the warmth of sleeping bags with synthetic insulation is trickier due to the variety of proprietary materials. This makes a comparison between manufacturers nearly impossible. However, the fill weight should allow for a rough comparison; as with down, more insulation is warmer than with less. The REI Co-op Magma 15 has the highest fill weight of any down bag we tested, yet it wasn't the warmest of the down bags we tested (even with a matching 850 down fill power). In several cases, lighterweight bags proved even warmer in testing due to combined design choices that enhanced their insulating properties.
In an attempt to standardize sleeping bag warmth measurements, the European Committee for Standardization developed the EN 13537 standard, which is a test designed to provide consistent temperature ratings for all sleeping bags. The ISO (International Standards Organization) is a new entity that has joined the discussion, overseeing bag testing using a method that is almost identical to the EN bag test. Though the specific details of testing protocols may arbitrarily favor certain designs while offering limited information about warmth under real-world conditions, the EN and ISO ratings seem more accurate than the manufacturer-advertised temperature ratings of the past. Feathered Friends, The North Face, Western Mountaineering, and Teton Sports are three brands in our review that do not currently participate in EN or ISO testing for the models included.
Not every brand participates in EN or ISO testing. We list these temperatures when brands make them available; if they don't, we list them as 'Not Available' in our specifications chart, underneath our Product Comparison Table.
EN and ISO ratings can be confusing to understand at first. You may see a listed temperature on a sleeping bag, like 30°F, and assume that you'll be comfortable in that bag at that temperature. But that's not necessarily the case. EN and ISO provide ratings at three different temperatures: Comfort, Lower Limit, and Extreme.
Comfort: This rating is recommended for most users. It represents the lowest temperature at which a “standard woman” or cold sleeper can get a comfortable night's sleep.
Lower Limit: This is the lowest temperature at which a “standard man” or warm sleeper can sleep for eight hours without waking due to frigid temperatures.
Extreme: This is a rating for survival only, indicating the lowest temperature for a person to avoid hypothermia, though significant discomfort and danger remain possible.
Due to the above issues and subjectivity, we evaluated warmth using real human testers. We spent three nights in each model in a 48°F room, putting each bag to the test outdoors when temperatures dipped into the 20-35°F range, and even beyond. We compared the bags to each other and their EN/ISO ratings. The difference between the warmest and coldest bags is more significant than each company's ratings imply.
Tents create a warmer sleeping environment, which is something to be aware of if you want to leave them behind, as our testers often do. Credit: Jack Cramer
Fit and design also affect warmth. If your sleeping bag is too roomy, your body has to heat all that extra space, making you feel colder. This goes for length and girth, so shorter humans might want to check out our women's sleeping bag review, or a bag like the REI Co-op Trailmade 25 or Exped Terra 15, which features shorter models. A bag that fits too tightly causes your body to squeeze against the insulation, reducing its ability to trap heat. For maximum warmth, size your bag to fit snugly but not tightly.
Some sleeping bags, like the REI Trailmade and Exped Terra, are available in multiple sizes. Getting a bag that properly fits you is key to maximizing warmth and comfort. Credit: Arthur McMahon
Other design features that can affect warmth are zipper baffles and draft collars. Both features are extra bits of insulation positioned to stop heat from escaping from the zipper and hood, respectively. They're unnecessary for a summer backpacking sleeping bag, but we like to see them on bags rated 20°F or below. The Rab Neutrino 400 and Western Mountaineering UltraLite are two bags that feature excellent draft collars. While draft collars are great for warmth, they can sometimes detract from comfort, making the user feel somewhat restrained, especially when tossing from side to side. This is not the case with the Sea to Summit Spark Down 15 draft collar, which kept our body heat sealed in nicely without smothering us in our sleep.
The Sea to Summit Spark Down 15 kept our head and neck perfectly warm. Credit: Elizabeth White
As you'd probably guess, a higher score in this test means a warmer bag. However, a high score doesn't necessarily mean it's the best bag for you. More likely, if you're looking for a bag for most 3-season conditions, a score of 7 or 8 will probably be enough. For most hikers, the bags with the highest warmth rating are best suited for frosty nights at elevation or perhaps the shoulder seasons. For folks whose backpacking season starts on April Fool's Day and goes through Halloween, consider a 9 or 10.
Keep in mind that for your bag to perform up to its temperature rating, you need a quality sleeping pad. We know some folks sleep colder than others, but in some cases, we believe the culprit is an inadequate sleeping pad.
Additionally, take care of your bag to get the most out of its insulation – it needs to be laundered from time to time to maintain its loft. It also helps to already be somewhat warm when you get into your bag, to be well-fed and hydrated, and to remove any wet clothing that might chill your skin. You can always boil water, put it in a Nalgene, seal it tightly, and put it in your bag for hours of added warmth.
All bags are designed to be used with a good sleeping pad to insulate you from the ground. Without one you'll be lucky to sleep at all near a sleeping bag's temperature rating. Credit: Jack Cramer
Weight
The longer or more challenging your trips are, the more important weight becomes. Experienced backpackers know that the saying “every ounce counts” is a result of spending days on trail — the more weight in your backpack, the more you're going to feel it mile after mile. Generally, you want to keep your backpacking kit as light as possible, while considering your budget and other comforts, of course. A sleeping bag's weight is a consequence of the amount and type of insulation, the specific fabrics used, the bag's dimensions, and the nature of the features. Generally, higher-quality materials weigh less, but they cost more. Switching to a shorter zipper or a trimmer fit is one potential way to reduce weight, but it can affect comfort. We tested and measured all the bags in this review in size Regular.
To evaluate the weight, we used a digital scale to weigh each bag separately, without any included items or compression sacks. Although we report the weight of stuff sacks individually, scores are based solely on the bag's weight. This is under the assumption that most users will opt for an aftermarket compression sack that is more effective at compression and potentially lighter weight.
The Hummingbird is our favorite backpacking sleeping bag for when we want to go light. Pair it with a backpacking tarp to really trim the weight of your overnight kit. Credit: Jack Cramer
There is a 3-pound difference between the lightest and heaviest bags in this review: the Feathered Friends Hummingbird UL 30 (our lightest bag) and the Sea to Summit Boab Synthetic 15 (the heaviest bag we tested). That's an enormous difference in the world of backpacking, where you're sometimes carrying a week's worth of necessities on your back. If you select similarly heavy gear for your entire overnight kit, the weight difference will quickly grow to double-digit pounds. That could easily be the difference between making it to camp before dark or turning back before your knees and back give out.
The Feathered Friends Hummingbird weighs several pounds less than the heaviest bag we tested, which was the Sea to Summit Boab.
A sleeping bag is one of the top three heaviest items backpackers carry. A really light model, like the 1.3-pound Feathered Friends Hummingbird UL, is one of the most ultralight-friendly bags we tested, and can cut several pounds off your load. While this bag is pricey, we think it's well worth it for your joints and overall enjoyment. Other ultralight-friendly bags worth considering are the Western Mountaineering MegaLite (1.5 pounds) and Sea to Summit Spark Down 15 (1.6 pounds) for their exceptional goose down insulation, comfort, and warmth. Both are pricey, but if you plan to do a lot of backpacking or are considering a long thru-hike, we think it's worth the cost.
A more affordable, lightweight choice for the budget backpacker is the Mountain Hardwear Bishop Pass 15. At 2.3 pounds, it's not the lightest bag, but the few extra ounces are easy to overlook when you're spending half as much.
Take ultralight principles to the extreme and it's possible to trim enough weight off your overnight pack to enjoy activities like climbing, skiing, or backpacking for weeks on end. Credit: Jack Cramer
Comfort
For many, sleeping outdoors can be much harder when you're at the mercy of Mother Nature and zipped into an ill-fitting tube. Although some can sleep like a log on a busy city bus, many find the unfamiliar, restrictive environment of a backpacking sleeping bag disruptive. If you're in the former group, rejoice! You can ignore our comfort evaluations. The latter should devote special attention to this assessment.
To evaluate comfort, we considered several factors: the dimensions and fit of each bag, the loft or fluffiness of the insulation, the feel of the interior fabric, and, in some cases, the noisiness of the materials. In this test, the bag's comfort score is our best subjective judgment of its fit, loft, feel, and noise performance.
The biggest comfort difference between the narrow Hummingbird (top) and the roomy Forte is around the hips and feet. Credit: Ian McEleney
Three bags provide impressive comfort in two ways worth discussing. The Nemo Forte 20 is shaped like a broad hourglass rather than a tapered sarcophagus. The bottom of this hourglass offers an extra 12 (or more) inches of girth compared to ordinary bags, which gives side and tummy sleepers ample room to stretch their legs in any direction. This extra space for the hips and feet was noticeable even when compared to tapered bags with similar shoulder measurements. The NEMO Disco Endless Promise 15 is the same shape but four to six inches wider for even more space to move around. And the Sea to Summit Boab Synthetic 15 has a rectangular shape with a zipper that fully unzips around the entire footbox, turning the one-person bag into a two-person blanket.
The Disco 15, and most Nemo sleeping bags, provide tremendous space at the foot of the bag which makes stretching your legs much more enjoyable. Credit: Jack Cramer
Though we like the unique shape of the Nemo bags, the insulation is not as lofty as it appears, and the other materials aren't exceptionally soft. The final standout in our comfort tests is the Western Mountaineering MegaLite, which covers all the bases. Its 850+ fill power down and ExtremeLite fabric combine to create a cozy cocoon of luxurious loft. While it has some of the most space around the shoulders and torso, the standard tapered mummy shape and narrow footbox won't be appreciated by everyone.
Ultra-premium loft on the left, regular loft on the right. Credit: Ian McEleney
When sleeping in some of the most uncomfortable conditions in the High Sierra in late October with whipping winds and cold temperatures, the Sea to Summit Spark Down 15 felt like luxury. The 53-inch hip girth and 61-inch shoulder girth were just roomy enough for us to roll around in our sleep, but slender enough not to let too much dead space accumulate cold air. The footbox is 40 inches, which gave us enough space to stretch out. While we weren't exactly starfishing this bag, it wasn't restraining either.
The Sea to Summit Spark Down 15 nylon fabric feels more like silk. Credit: Elizabeth White
The Spark's main allure is its velvety nylon fabric — it feels light and feathery to the touch, like sleeping on a cloud. It occasionally makes soft crinkly sounds when we shift around in the bag, though they weren't loud enough to disturb our ears (or our tent-mates). That said, we do have some durability concerns with the fabric on both the liner and the shell, as it's almost as thin as you can get and could rip more easily than other fabrics. However, you shouldn't be bringing your sleeping bag around sharp objects anyway.
If you want some wiggle room in your bag, the Nemo options are a great way to go. Credit: Jack Cramer
As these examples illustrate, a bag's comfort is inherently subjective; choosing one that matches your preferences is essential. Those who don't mind a mummy bag will likely prefer the luxurious materials of the MegaLite. Meanwhile, side sleepers may find the innovative, spacious shape of Nemo's Forte and Disco, or the boxy Sea to Summit Boab, superior.
The long, rectangular shape of the Sea to Summit Boab provides plenty of room for your limbs to spread out. Credit: Arthur McMahon
To some, noise can be a big concern. For others (like heavy sleepers), it's not that big of a deal. Our crew's lightest sleepers immediately noticed that certain crinkly fabrics could disturb their sleep. This issue was most noticeable with the Pertex Endurance shell of the Feathered Friends Hummingbird UL. Though earplugs easily resolve this issue, you should probably avoid this fabric if you're concerned about noise. Fortunately, the Hummingbird can also be purchased with a much quieter, more durable, and cheaper—but slightly heavier—Pertex Quantum shell fabric.
We packed each sleeping bag into the same compression sack to find out which ones compress into a compact size with ease, like the Western Mountaineering MegaLite. Credit: Elizabeth White
Packed Size
The bigger your backpack, the further its mass is from your center of gravity. This can make hiking with your pack more strenuous, leading to premature fatigue and ultimately less fun outdoors. Sleeping bags are usually one of the largest items in your overnight pack. Therefore, getting a bag that compresses smaller is a good way to reduce the size of your load and overall burden. As with weight, the more time you spend on the trail or the more challenging the trail is, the more important this becomes.
All the bags we tested include a regular stuff sack or compression sack for storing them inside your backpack. The regular stuff sacks, however, are ineffective at compressing a sleeping bag. So, to evaluate packed size fairly, we used the same 11-liter Granite Gear Air Compressor compression sack to measure each bag's minimum compressed volume. We also noted how strenuous it was to stuff each bag back into its individual pack.
Some bags take more effort to pack away than others. The Exped Terra 15 is a down bag that stuffs easily into its spacious compression sack. Credit: Arthur McMahon
By and large, the compressed volumes we observed corresponded closely with the weight of each bag. A couple of exceptions are the Mountain Hardwear Bishop Pass 15, which compresses roughly 10% smaller than its weight would suggest, and the Western Mountaineering UltraLite, which packs down 15% larger than comparable bags. The Western Mountaineering MegaLite and Enlightened Equipment Enigma 20 also packed away super easily, saving us both space and time.
Compression sacks help reduce the packed size of your sleeping bag. Most of the bags we tested came with a regular, non-compressive stuff sack. Credit: Jack Cramer
Although these discrepancies are worth noting, all the bags included in this review are small, especially compared with cheap car-camping bags or the backpacking behemoths of yesteryear. So, we don't think packed size should be the crucial factor in distinguishing today's sleeping bags. The Sea to Summit Boab Synthetic 15 is the one exception in our testing that may be too big for some to carry in their backpacks. Depending on your plans and budget, however, it may be worth checking the difference in packed size between a premium and budget backpacking sleeping bag you're considering.
The Enlightened Equipment Enigma 20 is an 850 FP down bag that stuffs down to a compact 7 liters, even without a compression sack. Credit: Arthur McMahon
Features
“Features” is a catch-all category encompassing the performance characteristics that our other evaluation criteria did not address. Often, this evaluation separates high-performing inexpensive bags from lower-performing models like the Teton Sports Trailhead and Big Agnes Anthracite 20.
Our assessment considers extras such as small stash pockets, sleeping pad attachment systems, and the bag's zipper quality, among other things. These are quality-of-life extras that enhance the overall experience on trail, making your tent feel a little more like a home away from home. We also assess the overall execution of the bag. Are all of its materials similarly durable? Do its warmth, weight, and dimensions make sense for its intended use?
A zippered interior pocket, such as this one on the Exped Terra 15, provides a secure spot to stow odds and ends, like a smartphone, headlamp, or freeze-sensitive water filter. Credit: Arthur McMahon
Dark interiors turn the bag into a black hole for small items stuffed away, like a headlamp or electronics, while bright liners make them easy to find. Both Nemo bags, the Trailmade 25, the Bishop Pass, Enigma 20, Sea to Summit Spark, and several others feature light-colored liner fabrics, often yellow.
Lost something inside your sleeping bag? Bright liners can help you easily see what you're looking for. Credit: Ian McEleney
We're also big fans of the full-length zippers on the Feathered Friends and Western Mountaineering bags. Both companies' bags have an internal strip of plastic in the adjacent fabric to direct the fabric away from the zipper teeth and reduce the risk of snagging. Feathered Friends bags also feature a Y-shaped, anti-snag zipper slider. The Sea to Summit Spark and Trailmade 25 are also marketed as anti-snag, and while the design does the trick most of the time, they weren't completely fool-proof, and our zippers did snag on occasion.
The Feathered Friends bags that we tried feature anti-snag, Y-shaped zipper slides. They also have an internal strip of flexible plastic to prevent the zipper from snagging on the interior lining. Credit: Arthur McMahon
Most sleeping bag zippers include a pair of the interlocking pins on one end that allow you to connect and disconnect the left and right sides of the zipper. Easy to overlook, these tiny pins are necessary for restarting a zipper if it gets misaligned. Some designs sew the zipper ends directly into the bags — this design creates a possible problem. There is always a chance that the teeth will get misaligned or the zipper slider will pop off from one side. With most bags, just restart the slider at the pins. But if misalignment occurs in the backcountry with the The North Face Cat's Meow, it may be impossible to restart the zipper or close the bag properly.
The pins at the bottom of most zippers (center) are necessary to get it restarted if the teeth become misaligned. Unfortunately, the bags on the left and right both lack these important pins. Credit: Jack Cramer
Other Notable Sleeping Bags We Tested
Even though we've tested tons of sleeping bags over the years, not all of them make the final cut for our comparative selection. However, that doesn't mean that they aren't still lightweight, warm, comfortable, and a very reasonable option for your next backpacking trip. Below are the bags that didn't quite make the cut, but that are still well worth considering:
Feathered Friends Swallow 20 YF – This is a lightweight, 900+ FP bag that's under 2 pounds and has a slightly larger packed volume than similarly warm bags like the Western Mountaineering Megalite. This bag gets seriously warm and is a great option for colder-weather trips in the fall and spring.
NEMO Forte 20 – A roomy and fairly warm bag that won't break the bank, it's packed with synthetic fill and has a unique “Classic Spoon” shape that's made for side sleepers. It's also made entirely of recycled materials, and the entire bag is recyclable at the end of its life.
Rab Neutrino 400 – This bag straddles the line between premium and mid-tier, and performs like it as well. It nearly stands toe-to-toe with some of the more premium down bags we tested, and you can save a little bit of money by choosing the Neutrino.
The Rab Neutrino is a super comfortable sleeping bag, it's just a bit bulky compared to other, more modern options. Credit: Jack Cramer
Conclusion
Deceptive marketing claims, a tremendous number of models on the market, and preposterous prices make shopping for sleeping bags a daunting task. Our extensive testing process and thorough assessments aim to crack the code.
Gearing up for a backpacking trip starts with the right backpacking gear. We have in-depth reviews to help you easily pick out the other big items you'll need: a comfortable backpacking backpack, a reasonable packable backpacking tent, and a warm sleeping pad.
