Getting a good night’s rest can make or break a camping trip, which is why a sleeping bag is arguably the most important piece of gear you’ll need for any overnight outdoor adventure.
After testing 13 excellent sleeping bags for three-season use, I found the moderately priced Nemo Forte Synthetic Sleeping Bag (available in men’s and women’s versions) to be the most versatile and comfortable bag for car camping and light backpacking. For a less expensive but comparatively warm sleeping bag, the Coleman Big Bay 20° Mummy Sleeping Bag is my top choice for around $100. The North Face One Bag Sleeping Bag is a worthy upgrade that can add or remove layers to keep you comfortable year-round. And the Montbell Down Hugger 650 #2 stands out for its ultralight properties that make it a worthy bag for three-season backpacking trips.
Although a tent and sleeping pad are essential parts of the sleep setup, the humble sleeping bag is the real workhorse in the equation, keeping you warm, dry and comfortable throughout the night.
The following is a list of all the winners from the testing process:
As a writer who’s covered outdoor gear for nearly a decade, I’ve tested hiking and camping gear on behalf of brands like REI, and as a gear columnist at Outside, I’ve tested various equipment including sleeping bags, sleeping pads, cots and tents, and I’ve spoken to dozens of outdoor pros along the way.
For this story, I interviewed multiple experts, asking them everything from how to choose the right style and insulation type to how we should interpret temperature ratings and fill power, and how to best care for sleeping bags when they’re not in use. I spoke with Jeremy Cronon, an outdoor guide and former field instructor who’s now the expedition equipment lead and outfitting manager at National Outdoor Leadership School (NOLS) Rocky Mountain. Cronon manages the outfitting department, ensures all the gear is expedition-ready and outfits students as they pass through the school.
I also interviewed Austin Robbs, director of equipment and accessories at Patagonia. (Patagonia makes sleeping bags, which I chose not to test this round because I only considered bags below $400 within specific parameters.) Before Patagonia, Robbs had about a decade’s worth of experience as a product leader in the outdoor industry, most notably at The North Face, where he worked on technical equipment.
I also spoke with Fashion Institute of Technology (FIT) assistant professor Preeti Arya, who teaches courses on finishes, fabric development and performance textiles. Arya discussed sleeping bag design, including features, materials and insulation options, as well as how sustainability factors into the decision-making process.
How I Tested The Best Sleeping Bags
The best sleeping bag must keep you comfortable throughout the night in the climate it was designed for. Beyond that, it needs features that go hand in hand with the type of camping you plan to do. I established testing criteria to determine which ones would be versatile enough for car camping and light backpacking. All the sleeping bags I tested are in the 15 to 30 degree Fahrenheit range, which is suitable for most three-season use, depending on where you live. While these sleeping bags will be sufficient for most people from spring through fall, you’ll need a dedicated cold-weather sleeping bag for winter camping.
For this round of testing, I only included sleeping bags under $450 and chose models to fit a wide range of bodies and sleeping styles, including bags to accommodate side, back and stomach sleepers. I looked for those that come in multiple sizes (usually regular and long) and included mummy, rectangular and hybrid bags. I left out double sleeping bags, as most rectangular bags, and even some mummy bags, can be zipped together. I tested synthetic and down sleeping bags but only considered down that’s received a third-party certification like the Responsible Down Standard (RDS) or equivalent. For all the sleeping bags, I looked for recycled materials and third-party certifications like Bluesign or Oeko-Tex, and I noted other verifiable sustainable attributes. I also looked at warranties, prioritizing brands with excellent return policies or product guarantees.
I slept in each bag overnight, napped in them and lounged around to get a sense of how they felt. In addition, I conducted controlled tests using an internal thermometer probe to evaluate heat retention, packed them in their stuff sacks repeatedly and laundered each bag. While testing, I paid close attention to the following:
Comfort: “Comfort is the most important thing, especially if you’re transitioning from car camping to one or two overnights backpacking,” says Cronon. “You’re probably going to spend more time sleeping than you are hiking, so having a bag that is comfortable, even if it’s a little bit bulkier or a little bit heavier, is going to be a better entry point to the world of sleeping outside in comfort.”
How a sleeping bag feels is largely a matter of personal preference, and that sense of comfort depends on how a person sleeps, the environment they sleep in and the bag’s design. A lofted 10-pound bag is decidedly more comfortable than an ultralight bag made for thru-hiking, so I made sure to consider what activities and temperatures the bag was designed for when evaluating comfort. I scored each bag on how well I could move around within the bag and the feel of the fabric, and I looked for great hood design, easy-to-use zippers, pockets, seam placement, baffle construction, draft tubes, footbox design and ventilation.
Warmth: Because everyone sleeps differently, evaluating warmth is rather tricky. To get a baseline for how well the sleeping bags retained heat, I used a wire probe thermometer and 100-degree hot water bottles. I placed the bags in a 40-degree room and checked the temperature of the water every couple of hours. In the end, the temperature of the water bottles was within a few degrees of one another, which means these bags are appropriate for the temperature range given. I also slept in each bag overnight (as did my partner) and made note of which ones kept me toasty and others that left me chilly.
Ease Of Use: A good sleeping bag will be easy to get into and out of, easy to stuff into its sack and stow and the features—like hood drawcords that pull tight and zippers that don’t snag—will work as intended. I took note of anything that made the bag more or less usable.
Packability: For packability, I looked at weight and packed size. When car camping, packed size and weight are less of a concern but remain important variables to consider as trunk space fills up quickly. For this reason, I eliminated the large rectangular flannel-lined bags in favor of more portable ones. When backpacking, on the other hand, space and weight are paramount, so the smaller a bag packs down, the better. I didn’t skew too far into ultralight territory, as these options are pricier and not usually as plush.
Extra Features: Features like hoods, fleece-lined footboxes, drawcords and pockets are nice to have, but they add cost to a sleeping bag—and they can compromise sleep if poorly positioned. When looking at the features of a bag, I considered whether they added value without impacting comfort or performance.
Durability: I checked for any signs of wear during typical use, and I laundered each sleeping bag once according to its particular care instructions, evaluating the designs for shrinkage, damage and any changes to the insulation (like whether the fill bunches or moves out of place and creates a cold spot). I used a mild liquid detergent on my front-loading machine’s normal cycle and tumble dried them on low heat.
Value: Typically with sleeping bags, the better the insulation, materials and features, the higher the price. For each bag, I made a value judgment that weighed price against features and performance, looking for down bags at a lower cost that performed really well, or synthetic bags with a ton of features.
Versions: Women’s regular | Women’s long | Men’s regular | Men’s long | Temperature Rating: 20 degrees Fahrenheit | Insulation: Synthetic | Shape: Spoon | Length: Varies by size | Dimensions: Varies by size | Minimum Weight: 2.87 pounds | Packed Size: 14 x 8.5 inches | Sustainability Attributes: 80% post-consumer recycled insulation | Warranty: Limited lifetime
- Almost any outdoor adventure and type of sleeper
- Those who want a high-quality car camping bag that can double as a backcountry bag
- Those who want the warmth of a mummy bag balanced with the movement of a rectangular bag
- You really need to spread out when you sleep
For the person who likes to backpack in the backcountry as much as they like to set up a tent at the local campground, the Nemo Forte is a solid choice for nearly any outdoor adventure. The unique shape of this sleeping bag makes it a best-of-both-worlds bag; it isn’t quite rectangular or mummy-shaped, but rather what Nemo calls a spoon shape, which is less tapered, with extra wiggle room around the elbows and knees. Of the seven synthetic sleeping bags I tested, the Forte is the one that feels the most like down, and I was comfortable sleeping in all positions, especially on my side. The Forte is my top choice because it excels across testing categories, and the supple, lofty material adds coziness that you don’t often find in similarly priced synthetic bags.
The features of the Forte add to its performance without including any frivolous details that don’t add value. The two-way zipper glides nicely and allows you to open the bottom of the bag to vent out warm feet. The bag’s shape keeps it close to the body for optimal heat retention while allowing for nearly as much movement as you get with a standard rectangular bag. And the hood and blankety neck collar add comfort around the head and provide a warm, tucked-in feeling that makes for a great night’s rest.
For a bag that feels this cushy, the Forte packs down small enough to take on backpacking trips where you’re hiking long miles. It also comes with a compression stuff sack (not all bags do), which helps it take up even less room on or in your pack (it also comes with a sizable mesh bag for home storage). The Forte is also easy to care for and laundered wonderfully, with no insulation bunching or shifting during a normal cycle through the washer and dryer. Although my bag still looks and functions as it did on the first day, Nemo backs its sleeping bags with a lifetime warranty against manufacturing defects, provided you take care of the bag correctly. Even more notable is that Nemo offers spare parts and full repair services for gear that needs extra TLC to continue performing.
The Forte is available in men’s and women’s versions, which have opposite-sided zippers, allowing you to zip two bags together to create a double sleeping bag. Both models come in regular and long, with slightly varying dimensions, but the main difference is in the comfort rating. Both bags have a temperature rating of 20 degrees Fahrenheit (and are available in 35-degree versions if you’re looking to spend less and sleep in warmer environments), but the women’s version has a comfort rating of 20 degrees Fahrenheit, while the men’s has a comfort rating of 32 degrees Fahrenheit, meaning the women’s bag will keep you comfortable in slightly lower temperatures. If you fit the bag’s dimensions but want a tad more insulation, opt for the women’s bag; if you’re worried about overheating, opt for the men’s version.
If you’d prefer a down sleeping bag and are willing to pay about $100 more, the Nemo Disco (available in a men’s and women’s version) is the same design but made with 650-fill-power down. The Disco is even plusher, more comfortable and more packable than the synthetic Forte. According to Arya, it’s also more sustainable because it’s made with biodegradable insulation that adheres to the RDS. Third-party certifications, which typically audit the process by which your down goes from farm to sleeping bag, add authenticity, she says, but they cost a little more, too.
Versions: Regular | Temperature Rating: 20 degrees Fahrenheit | Insulation: Synthetic | Shape: Mummy | Dimensions: 79 x 32 inches | Sustainability Attributes: No third-party certifications | Warranty: 5-year limited
- People looking for an affordable and reliable sleeping bag for car camping
- Three-season use in most environments
- You plan to spend as much time backpacking as car camping
The Coleman Big Bay is a warm, comfortable and moderately priced sleeping bag that will see you through many nights of car camping and even a beginner overnight backpacking trip. When not being used outdoors, the Big Bay is a great option to have on hand for sleepovers or as part of your emergency kit. For around $120, it’s a cozy, capable bag for three-season camping in most places.
One of the nicest things about the Big Bay is that it’s a mummy bag that doesn’t feel like a mummy bag. It isn’t as torpedo-shaped as a lot of the mummy bags I slipped into, so it didn’t leave me feeling claustrophobic, and the slightly wider dimensions and roomy footbox make it easy to move around once inside the bag, so you can twist and turn all night without getting tangled up. In the heat-retention tests, the Big Bay bag fell in the middle of the pack, outperforming some sleeping bags that cost twice as much. The footbox is lined with fleece, which adds coziness and warmth to a vulnerable spot that’s often the first to get cold. The oversized neck collar and cinchable hood fit well and helped trap heat throughout the night.
The Big Bay is outfitted with a two-way zipper that runs in a J-shape down one side and across the shins. This allows you to unzip just the foot area to vent out if you get too hot, and your feet are still resting on the sleeping bag rather than on the cold ground. There’s also a draft tube that runs the length of the zipper to prevent warm air from escaping. The large zipper is easy to pull and glides without getting caught in the fabric.
The Big Bay packs down to a decent size that fits in a trunk; it’s not nearly as small as the sleeping bags designed for carrying on your back for long treks, but it’s more compact than rectangular bags like the REI Co-Op HunkerDown 20 and the Sierra Designs Boswell 20°. It’s also available in a Big and Tall Contour version for $130, which is a few inches taller and broader in the shoulders and hips. The Big Bay is one of the easiest bags to maintain out of those I tested, needing no special care and handling a standard laundry cycle fine.
Versions: Regular | Long | Temperature Rating: 5, 20 and 40 degrees Fahrenheit | Insulation: 800-fill-power down and synthetic | Shape: Mummy | Length: Varies by size | Dimensions: Varies by size | Minimum Weight: 2.18 pounds | Packed Size: 11 x 14 inches | Sustainability Attributes: RDS | 80% post-consumer recycled polyester fill | Warranty: Limited lifetime
- Versatile use that operates in a variety of climates
- Someone who only wants to own one sleeping bag but likes to camp year-round
- You don’t need the added versatility
A sleeping bag with interchangeable layers for different environments might seem gimmicky, yet the North Face One Bag is anything but. Using the same bottom base, this three-in-one sleeping bag allows you to swap out the standard 20-degree 800-fill-power down mid-layer for the lighter synthetic top layer rated for 40 degrees Fahrenheit. You can also use both layers together for a cold-weather 5-degree bag. Color-coded zippers that run the perimeter make changing layers easy, and the material looks and feels great, with a big puffy hood and draft collar that make it ultra cozy.
The thoughtful design of the One Bag makes it truly transitional between most climates and suitable for most sleepers. The bag utilizes both recycled synthetic and down insulation, and although it’s a mummy bag, it’s got a vaulted footbox and room to toss and turn without feeling restricted (I can roll around and pull my knees up inside the bag). In the 20-degree configuration, the One Bag was on par warmth-wise with my top pick, the Nemo Forte, and it’s just as comfortable. The ability to zip off the top layer of the sleeping bag means that you also have two comforter options—a bonus for cozying up for a mid-afternoon hammock nap or warming up around the fire on a chilly night.
The One Bag doesn’t have the smallest packed size, but it’s much more portable than the big synthetic regular bags. At around 4 pounds in its 5-degree configuration, it’s heavier than most performance bags designed for backpacking (all those zippers add weight), but it feels extra plush when compared to those sleeping bags. For a short backpacking trip, it’s more than capable (you can also leave an unnecessary layer at home to save even more weight and space). The bag also comes with a fleece-lined compression sack that you can use as a pillow.
More zippers mean more potential failure points and more fabric snags, but I found the zippers glided well—they caught the fabric only a couple of times during the many unzips I performed. The bag was easy to launder, and like the other top picks, the insulation remained in place after a standard wash and dry cycle. Typically I’d be wary of a sleeping bag that purports to do it all, but the North Face One Bag delivers on performance at a price that’s decent given the overall value (and you can sometimes find it on sale at retailers like REI for under $300).
Versions: Regular | Long | Temperature Rating: 25 degrees Fahrenheit | Insulation: 650-fill-power down | Shape: Mummy | Length: Varies by size | Dimensions: Varies by size | Minimum Weight: 1.98 pounds | Packed Size: Varies by size | Sustainability Attributes: No third-party certifications | Warranty: Limited lifetime
- Backpacking and thru-hiking
- Three-season use with a lower limit of 20 degrees Fahrenheit
- Ultralight packers or travelers who want to take their sleeping bag with them
- You won’t be carrying your sleeping bag on your back
If you’re looking for a plush, lightweight mummy bag that will keep you warm in most conditions outside of winter, the Montbell Down Hugger 650 #2 is an exceptional choice. For a narrow and steeply tapered bag, it’s easy to move in thanks to an ingenious diagonal baffling construction and stretch stitching. Once inside, the bag stretches to move with you, so if you want to turn on your side or move your legs freely about, you can (which isn’t the case with many ultralight backpacking sleeping bags). Although not as thick and cozy as bags for general camping, the Down Hugger is soft and lofty, so you can take it to the campground or sleep in the backyard and feel sufficiently bundled up.
When I first crawled into the Down Hugger mummy bag, I was shocked by how roomy it became. The fabric is cut on a bias—rather than following the straight lines of the weave, the material is turned 45 degrees and cut on an angle—which gives it more stretch. Montbell also uses an elastic-stitch technique to create slight gathers in the quilting. Both my partner, who’s taller and leaner, and I felt like the bag conformed to our bodies and provided adequate warmth throughout the night (the bag has an ISO lower limit rating of 19 degrees Fahrenheit and a comfort rating of 30 degrees Fahrenheit, meaning that you’ll be okay in temperatures as low as 19 degrees, but you’ll feel comfortably warm in temperatures around 30 degrees). Inside the bag, I could curl into a ball, switch sides and pull my knees up without issue. The hood isn’t as roomy as others, but it is cozy and easy to cinch down, and the no-catch zippers save the supple fabric from snagging. The Down Hugger is available with left- or right-side zippers, which can zip together to make a double bag.
The Down Hugger has one of the smallest pack sizes of the bags I tested, and its weight hovers right around the 2-pound mark. While you can find even smaller and lighter backpacking sleeping bags, you’d be hard-pressed to find one more comfortable at this weight. When you’re deep in the backcountry without any of the comforts of home, a cozy sleeping bag can be the difference between having a miserable experience and a life-changing one. In the heat-retention test, the Nemo Forte and the North Face One Bag were a little warmer, but the Montbell Down Hugger was only a couple of degrees behind, which I deemed sufficient, given how much lighter it is as a result of the feathered insulation. The Down Hugger also has a draft tube to prevent heat from escaping and a lofty neck baffle (rather than a thick collar), which is standard fare for a backpacking bag, and I could tuck my face and neck inside the bag to keep warm.
Caring for down is a little more involved than a standard synthetic sleeping bag given the capricious nature of goose feathers. Still, after one cycle through the washing machine and dryer, the Montbell Down Hugger sleeping bag didn’t have any shifts in the down insulation, frayed stitching (which I paid close attention to) or changes in shape. Although I couldn’t verify that the down was responsibly sourced with an RDS or equivalent stamp of approval, Montbell’s website states, “Montbell never purchases down from operations that practice ‘live-plucking’ methods. We only utilize down plumes and feathers collected as a by-product of water fowl raised to meet the demands of the food industry.” Montbell offers a limited lifetime warranty against manufacturing defects. However, if your bag gets damaged due to wear and tear, the brand accepts clean items for repair at a reasonable cost.
Other Sleeping Bags I Tested
When I narrowed down the contenders list to the top 13 sleeping bags to test, I included only those bags I knew would perform well in one condition or another. Any of the sleeping bags on this list might be suitable for your needs and lifestyle, so read on to find out what makes them worthy of consideration, and why they didn’t quite make the winners’ circle.
Sea to Summit Altitude Women’s Down Sleeping Bag: The 25-degree women’s Altitude is the priciest sleeping bag I tested at $399, and it’s also the most luxurious. It’s made of ultra lofty 750-fill-power RDS duck down, and the shell fabric feels incredibly supple against the skin. The no-snag three-zipper system features a full-length zipper on one side and a half-length zipper on the other, saving weight and allowing you to slide in and out without issue. There’s also a short zipper below the feet for added ventilation, extra insulation in the footbox and a comfy hood. If cost isn’t a factor and you plan to backpack more than car camp, the Altitude is the most upgradable mummy bag on the list.
Sea to Summit Ascent Down Sleeping Bag: I also tested the Sea to Summit Ascent bag rated for 25 degrees Fahrenheit and determined the Altitude to be the more comfortable of the two. However, the Ascent is lighter and more packable. It has the same premium features, like a cozy hood, draft tube, large draft collar and no-snag zippers that all work to keep the cold out, but lacks the ultra plush feel of the Sea to Summit Altitude bag rated for slightly colder temps.
Kelty Tuck 20 Sleeping Bag: If you want to spend the least amount of money on a quality mummy sleeping bag that you can car camp with or carry on a short hike, the Kelty Tuck 20 is a synthetic bag that’s roomy, feels good to sleep in, retains heat and has a comfortable hood. It’s an excellent value for just under $100 and the runner-up for my value pick behind the Coleman Big Bay 20°, which edged it out slightly in comfort and warmth.
REI Co-op HunkerDown 20: The HunkerDown is a comfortable and roomy RDS-certified down sleeping bag at a decent price. The plush rectangular bag can unzip into a down comforter for lounging around the campsite. The zippers glide easily, and the design features a cushy neck collar as well as a large lofty hood, and while not the most formfitting, it fits a pillow and accommodates people who sleep with their arms above their head. For a slight upgrade in price, the Nemo Disco is a down bag that feels a little plusher and more personalized, but if you want down insulation and a rectangular shape, this is the sleeping bag for you.
Sierra Designs Boswell 20°: If you want to spend as little money as possible on a rectangular sleeping bag that you can use most of the year, the Sierra Designs Boswell 20° is roomy and reliably warm. It takes up the most space among the bags I tested, but for a car camping-only bag, it’s of average size for the under-$100 sleeping bags. The fabric does feel slippery next to the luxurious feel of bags that are much more expensive, but it’s plenty warm, and there’s more than enough room to alter sleeping positions throughout the night. It can also be fully unzipped and paired with a second bag to create a double bag.
Marmot Trestles Elite Eco 20 Sleeping Bag: The Marmot Trestles is light and packable, but the narrower fit feels more restrictive than other mummy bags with similar dimensions, and it felt less warm than other 20-degree bags. Because it doesn’t offer much movement, I ruled it too constrictive for most people looking for a casual sleeping bag.
Mountain Hardwear Bishop Pass 30F/-1C: The down-filled Mountain Hardwear Bishop Pass is lighter and easier to carry than the top overall pick, but it’s not as comfortable or warm and costs $35 more. The no-snag zippers won’t catch the fabric, and the hood cinches nicely around the face, but it tapers too sharply for what most casual campers would enjoy and doesn’t have the versatility of other bags on the list.
Ust Monarch Sleeping Bag: The Ust Monarch is another bag with multiple configurations to transition between climates, but it isn’t as warm or easy to use as my upgrade pick, the convertible North Face One Bag, and it doesn’t feel as plush either. There are two extra “wings” for layering up, but they’re attached with small toggles along the sides, which are challenging to fiddle with, especially with cold fingers in the dark.
How To Pick A Sleeping Bag
Like most outdoor gear, choosing the best sleeping bag requires prioritizing the features that suit your lifestyle. You must consider how you sleep, the environment you plan to sleep in and the type of camping you plan to do. “Try to sleep in the woods like you would sleep at home,” says Robbs. “Especially if you’re just getting started, sleep is going to be a massive part of those first camping experiences, and making sure that you set yourself up for success is pivotal.” With that in mind, here’s what to look for when choosing the best sleeping bag for you:
The most important thing to look for is a sleeping bag with the appropriate temperature rating for whatever environment you want to be comfortable in, says Cronon. “Temperature ratings are a complicated area for sleeping bags, since not all people sleep at the same temperature, and it’s not something that brands necessarily have to disclose very accurately across the board.” Some brands will do their own testing, but you’ll find that many popular outdoor brands use a standard EN test rating or an ISO rating, which will give you a few different numbers that serve as benchmarks.
“The EN test rating is the standardized system for measuring the warmth of sleeping bags,” says Robbs. “It’s a way of letting you know how much energy you have to expend to stay at a certain temperature throughout the night.” These bags have three different ratings: an extreme, a lower limit and a comfort rating. With the extreme rating, you won’t sleep well, but you’ll stay alive. The lower limit is the lowest temperature at which the average person in long underwear and socks might sleep through the night. And the comfort rating refers to the lowest temperature at which a person will sleep cozily all night. “So the same bag that scores a 20-degree limit rating gets about a 30-degree comfort rating,” Robbs explains. What’s even more confusing is that many brands use the comfort rating for women’s bags and the lower limit rating for men’s and unisex bags because testing suggests women lose more body heat during the night than men.
These ratings serve as a baseline to help you decide which bag is right for you, but you also need to factor in the type of shelter you’re sleeping in, what clothes you’re sleeping in, what surface you’re sleeping on and the kind of sleeper you are. “For general car camping in a three-season environment, or if you’re in most of the continental U.S., a 20-degree bag will likely serve you from 50 degrees Fahrenheit all the way down to around freezing,” says Cronon. “In general, most folks actually sleep comfortably about 5 to 15 degrees warmer than whatever the lower limit on a sleeping bag is.” If you sleep warm and don’t plan to camp when it’s cold, consider paying less money for a 30-degree bag.
All the experts I spoke with agree that one of the primary things to consider when choosing a sleeping bag is the insulation type. Sleeping bags either have down feather insulation, synthetic polyester insulation (sometimes made of recycled material) or some combination of the two. There are benefits to synthetic and down insulation, and choosing one over the other comes down to considering the context of use.
“Synthetic bags are generally cheaper and take less rigorous care to maintain their loft, and you can use them in wet and dry environments. But they’re a little bulkier,” says Cronon. “Down is going to be lighter, loft up more and be fluffier for you when you’re going to bed.” But down doesn’t perform as well in wet environments, and it can be harder to manage, which is why Cronon sees more people trend toward down when they’ve had a bit of experience camping and sleeping outdoors.
A sleeping bag is not inherently warm; you have to warm it up yourself, which is why a big part of how well a sleeping bag performs depends on its shape. “Shape is all about efficiency,” says Robbs. Sleeping bags are generally rectangular, mummy-shaped or a hybrid. The closer-fitting the bag is to your body, the less space there is to heat up, but that comes at the cost of comfort. “If you have a big rectangular bag, you may be able to starfish and spread out and roll around very easily, but you have to keep all of that space warm for it to keep you warm.”
A mummy bag looks like the name suggests: It’s very formfitting around the head and shoulders, with a design that tapers around the feet. “When the mummy bag came along, that kind of revolutionized how much warmer sleeping bags could be, and they would take up less space,” says Cronon—but be wary. If the confined dimensions of a mummy bag leave you claustrophobic, consider a traditional shape that offers room to move and groove.
Some sleeping bags feel like a soft cloud that hugs you while you sleep. Others can feel slippery or plasticky, and while they might deliver in warmth, they don’t feel all that cozy to sleep in. Most sleeping bags are made from polyester (some incorporate nylon), and within that there’s a huge range of quality, which is determined by the compactness of the weave and how the filament has been produced, says Arya. “Good-quality material will have more compactness, more suppleness, more softness, more drapability.” Choosing a sleeping bag that feels good next to your skin will add to the experience when sleeping outdoors.
Fill power is a measure of the loftiness of a down feather—how fluffy it is. The higher the fill power, the more warm air it can trap and hold close to the body, so you need fewer feathers to achieve the same warmth. Generally, the higher the fill power, the more superior the down. “Good-quality down is very soft,” says Arya. “It looks like the tentacles of jellyfish floating in the water. If you blow on it, it moves. It’s very drapey, and it’s also warm.”
A 700-fill-power bag can be as warm as an 800-fill-power bag, but it takes more down for the 700-fill-power bag to achieve the same level of warmth (so the 700-fill-power bag will also be heavier). Typically, the higher the fill power, the higher the cost. For general camping and light backpacking, look for a fill power between 550 and 800. For an ultralight hiker, fill power will matter greatly because it can save weight while maintaining warmth through the night. For car camping, where weight isn’t as big of a concern, a bag with less fill power can be just as warm, but it will be a little heavier—which can actually add to the coziness factor.
“Baffles are channels built into the bag as a way of keeping the insulation where it’s intended to be to keep you nice and toasty warm,” says Robbs. Without baffles, the down insulation would gather at the bottom or sides of the bag, creating cold spots and uneven warmth. There are different baffling types, but quilt-through baffling is the easiest and often the cheapest. In quilt-through baffling, two pieces of fabric are stitched together. It keeps the insulation in the right spot but can potentially lead to cold spots because every time the sewing needle pierces the two materials, there’s now a hole where warm air can escape. A more sophisticated way of creating baffles is by inserting mesh or another lightweight fabric between the top and bottom layers to create channels or walls. This method typically retains more heat but costs a little more. You’ll notice these stitched rows running horizontally, vertically or diagonally across your sleeping bag.
Weight and packed size matter more when you’re backpacking, but even for car camping, you won’t want a sleeping bag that takes up half your trunk. If you plan to hike with your sleeping bag, look for a model that’s around 3 pounds or less. Less than 5 pounds is a good place to start for casual car camping and general use. Almost all bags come with a stuff sack, and some even come with a compression sack that crams the bag down into a smaller, more packable size.
Features like internal pockets and zippered vents are nice to have, but be wary of going all in on the extras that don’t make practical sense or add value for you, says Cronon. If you want the ultimate comfort, go all out on the accoutrements, but it’ll cost you. If you’re backpacking, traveling light or on a budget, be more discerning—more features lead to more potential failure points.
A well-fitting hood is one feature worth splurging on because it’s the spot we lose most of our heat from. A lofty draft collar around the neck and draft tubes along the sides are designed to prevent warm air from escaping, and both are valuable features to look out for, as is a footbox with added insulation if you’re someone who sleeps cold.
Do I Need A Women’s Specific Sleeping Bag?
Women’s, men’s and unisex sleeping bags often have slight dimensional differences, particularly in the shoulder, hips and knee areas. They sometimes have other differentiating features, like added insulation around the feet and core, but the biggest—and most confusing—difference is in the temperature rating. Men’s bags are often sold using the lower limit rating, while women’s sleeping bags are sold using the comfort rating, meaning that a 20-degree women’s bag and 20-degree men’s bag don’t necessarily match up warmth-wise. When making comparisons between sleeping bags, make sure you understand what the temperature ratings mean, and rather than looking at what gender the bag is being marketed to, find the sleeping bag that best corresponds to your body, your sleeping style and your personal preferences.