Best Ultralight Sleeping Bags of 2025

A sleeping bag is one of the most important pieces of gear when assembling a fastpacking or ultralight backpacking kit. Without a good night of sleep, trips can become miserable quickly, and if you spend the dark hours shivering, you’re probably not sleeping well. The best ultralight sleeping bags will keep you warm without weighing you down.

Whether you’re looking for an ultralight sleeping bag that will fit into a fastpack for mild desert nights or one that will keep you warm above treeline on a late fall trip, the weight of the bag matters. When combined with a slimmed-down kit, the best ultralight sleeping bags will keep your backpack light enough to run on many types of terrain and move quickly and efficiently at other times.

For this guide, we researched and tested over 25 sleeping bags over several years. We took them on spring, summer, and fall trips in the San Juans of Colorado, shoulder-season trips through the deserts of the Colorado Plateau, and countless trips through the Wasatch of Utah. We also tested sleeping bags in the damp climate of New Zealand, where keeping gear dry was a key challenge.

The sleeping bags in this guide are all light, warm, durable, comfortable, and packable. If you’re looking for one bag that can do it all, we recommend the Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree. If you prefer a quilt, we loved the Katabatic Gear Alsek 22F Quilt for its lightweight warmth. And if you’re looking for a sleeping bag for warmer temperatures or want to shave grams off your kit, consider the Western Mountaineering HighLite, which weighs only 16 ounces.

For more background information, see our buying advice, testing methodology, and frequently asked questions below the picks.

Make sure to check out our best fastpacking packs, best ultralight tents, best ultralight sleeping pads, and best ultralight backpacking gear guides as well!

Best Ultralight Sleeping Bags

• Best Ultralight Sleeping Bag With a Hood: Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree
• Best Ultralight Sleeping Bag With a Hood — Runner-Up: Montbell Seamless Down Hugger 800 #2
• Best Ultralight Sleeping Bag Without a Hood: Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree
• Best Ultralight Sleeping Bag Without a Hood — Runner-Up: Zpacks 20F Full Zip Sleeping Bag
• Lightest Ultralight Sleeping Bag: Western Mountaineering HighLite
• Lightest Ultralight Sleeping Bag — Runner-Up: Sea to Summit Spark Down Sleeping Bag – 30F
• Best Ultralight Quilt: Katabatic Gear Alsek 22F Quilt
• Best Ultralight Quilt — Runner-Up: Enlightened Equipment Convert Sleeping Quilt – 20 Degree
• Best Budget Ultralight Quilt: Outdoor Vitals StormLoft Down TopQuilt 15

Best Ultralight Sleeping Bag With a Hood: Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree ($629)

Pros:

• Comfortable
• Extremely warm
• Dimensions fit all testers well

Cons:

• Expensive
• Minimal draft collar

The Feathered Friends Swallow UL 20/30 Sleeping Bag—20 Degree is the warmest sleeping bag we tested. At 27 ounces, it is light enough to qualify as a fastpacking sleeping bag. It features light, durable, down-proof fabrics and is packed with 16.8 ounces of 950-plus fill down.

We slept in this bag on several fastpacking trips in temperatures ranging from 22 to 45 degrees Fahrenheit. Even at 22 degrees Fahrenheit, we didn’t feel like we were approaching the lower limit for this bag. It’s warm.

One downside to this bag is that it lacks an actual draft collar. To keep the cold out, you have to cinch the opening fairly snugly around your face. We prefer a draft collar that leaves the opening uncinched, which we think would be more comfortable.

Several of our female testers were happy with this sleeping bag’s 60-inch shoulder width. We believe the Swallow UL 20/30 is a truly unisex sleeping bag, fitting a range of bodies better than other wider and narrower bags. It’s also just insanely warm. This sleeping bag is on the more expensive end of the spectrum, but if you’re someone who spends a lot of nights out in the wild and can afford the price tag, we believe it’s a worthwhile investment that will last you a long time if properly cared for. The combination of features in this bag has led us to include it in our Best Ultralight Backpacking Gear guide.

This sleeping bag also comes in a 30-degree option for those who fastpack in warmer climates.

Type: Hooded Mummy Bag | Advertised Weight: 27 ounces (766 grams) in size regular | Actual Weight: 26.95 ounces (764 grams) | Fill Weight: 16.8 ounces (476 grams) of 950-plus fill | Temperature Rating: 20 degrees Fahrenheit | Packed Size: 7 x 12.5 inches (17.8 x 31.75 centimeters), 9 liters

Shop the Feathered Friends Swallow UL 20/30 Sleeping Bag - 20 Degree

Best Ultralight Sleeping Bag With a Hood — Runner-Up: Montbell Seamless Down Hugger 800 #2 ($455)

Pros:

• Lightweight
• Reasonable price
• Fewer seams improve thermal efficiency
• Nice draft collar

Cons:

• Lofts less than other options

For several years, the Montbell Seamless Down Hugger 800 #2 has been a go-to option for multiple members of the iRunFar testing team due to its warmth-to-weight ratio and somewhat lower price point. This 25-degree Fahrenheit bag has a unique baffle-free design that uses a combination of 800-fill down and a web of synthetic fibers to hold the down in place. It weighs 22.7 ounces in size regular.

Instead of using baffles to keep the down from shifting around and clumping up, Montbell uses threads of yarn to create something resembling a spiderweb inside the bag to trap the down where it belongs. This increases its ability to loft while preventing it from moving around in the bag. The design also reduces the number of seams in the bag. Since seams are one of the major spots for heat loss, this results in a warmer sleeping bag.

This bag seems a viable option well below its temperature rating, especially if you wear a layer or two for sleeping. The 10-denier Ballistic Airlight nylon taffeta shell doesn’t feel scary-light and has withstood multiple summers and shoulder seasons of use without any sign of wear. We also haven’t noticed any down leaking out.

The draft collar seals in warmth, and you can cinch the hood for the warmest setup. A draft tube along the zipper also prevents heat loss. The bag’s tapered shape makes it thermally efficient, yet still provides enough room to stretch out the legs after a big day.

While both of our testers for this bag were women in the mid-five-foot range, Montbell claims it will accommodate a person up to six feet tall. A long version is also available for taller people or those wanting extra space.

While this sleeping bag doesn’t loft quite as much as the Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree reviewed above, it’s still very warm. At a significantly lower price, it’s an excellent option for those looking for something that will keep them warm on nearly any summer mountain or shoulder-season desert trip.

Type: Hooded Mummy Bag | Advertised Weight: 23.9 ounces (677 grams) in size regular | Actual Weight: 22.7 ounces (644 grams) | Temperature Rating: 25 degrees Fahrenheit | Packed Size: 5.9 x 11.8 inches (15 x 30 centimeters), 4.7 liters

Shop the Montbell Seamless Down Hugger 800 #2

Best Ultralight Sleeping Bag Without a Hood: Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree ($529)

Pros:

• Very light
• Conservative temperature rating
• Comfortable
• The tapered mummy shape is thermally efficient
• It opens into a blanket

Cons:

• Expensive

Our testers agree that the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree can be used comfortably in a wider range of temperatures than any other sleeping bag on this list. Its versatility is just one of the many things that we loved about it. Hoodless sleeping bags are great for people who are going to fastpack with a hooded down jacket or a warm hat and don’t need extra warmth around their head.

The full-length zipper, which allows this sleeping bag to open into a blanket, makes it useful for both colder- and warmer-weather trips. It features a drawstring footbox closure, allowing for easy ventilation of the feet on warmer nights. We were impressed with how light and packable this sleeping bag was, given its warmth. It is stuffed with 14.7 ounces of 950-plus fill down and weighs only 25.8 ounces in a regular size on our scale.

We found this sleeping bag warmest and most comfortable when we kept the zipper underneath the body. In this orientation, we could unzip the bag to just below the hip, effectively using it as a quilt, a setup that we found comfortable and warm between about 27 and 45 degrees Fahrenheit.

Below about 25 degrees Fahrenheit, we recommend zipping up the sleeping bag all the way but keeping the zipper under the body. Even though most bags have a draft tube, zippers tend to be a cold spot. This zipper’s low profile makes it virtually imperceptible when lying on it.

When fully zipped, the shape is mummy-like for thermal efficiency, snugging around the legs. The Enlightened Equipment Convert Sleeping Quilt – 20 Degree, reviewed below, by contrast, is more egg-shaped, which is probably why it wasn’t as warm.

Our only gripe with this sleeping bag was the cord locks around the neck, a literally and figuratively small issue. The neck cinch features two shock cord drawstrings — one on each side — that are adjusted by cinching a small cord lock. Unfortunately, these cord locks cannot hold the neck opening closed, and even small movements uncinch the opening. To remediate this issue, we added an additional cord lock to each shock cord.

The Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree has truly outstanding versatility, making it our recommendation for anyone wanting only one sleeping bag. It’s cozy well into the teens, super light for its warmth, vents easily, and can be draped blanket-style for warmer nights.

You can get this sleeping bag in 20-, 30-, and 40-degree Fahrenheit options, so there’s something for any type of fastpacker.

Be sure to read our in-depth Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree review, too!

Type: Hoodless Sleeping Bag/Quilt | Advertised Weight: 25.2 ounces (715 grams) in size regular | Actual Weight: 25.8 ounces (731 grams) | Fill Weight: 14.7 ounces (417 grams) of 950-plus fill | Temperature Rating: 20 degrees Fahrenheit | Packed Size: 7 x 13 inches (17.8 x 33 centimeters), 8 liters

Shop the Feathered Friends Flicker UL Quilt Sleeping Bag - 20 Degree

Best Ultralight Sleeping Bag Without a Hood — Runner-Up: Zpacks 20F Full Zip Sleeping Bag ($519)

Pros:

• Very light
• Durable #5 coil zipper

Cons:

• Expensive for not having a differential cut
• 7-denier shell material is less downproof than others we tested

The Zpacks 20F Full Zip Sleeping Bag is a high-end quilt and sleeping bag hybrid that would be virtually perfect if it had a differential cut.

Weighing only 21.4 ounces in size regular, this is the lightest 20-degree Fahrenheit bag on our list. Its premium materials include 13.7 ounces of 900-fill DownTek goose down and 0.51 ounce/square yard, seven-denier liner, and shell fabrics. The fabrics are thin and light, allowing the down to loft fully. The shell is so thin that it’s scary, but it’s constructed with a tiny ripstop woven throughout, providing some peace of mind. Unfortunately, this material has proven to be the least downproof of any bag we tested, with little feathers leaking through here and there.

The bag has a long, two-way zipper, allowing you to open it nearly all the way on warm nights and zip it closed during the chillier times of the year. The neck opening cinches closed with a very thin shock cord, stretchy enough not to feel constrictive around the neck. The collar clasp is a plastic wafer clip instead of the snap most companies use, a move we can get behind because it’s secure and easy to use.

So now, you might be wondering what on earth could be wrong with this sleeping bag. First, it’s expensive, and potentially a little overpriced for what it is, especially compared to the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree, reviewed above. The Feathered Friends bag features more high-quality down — 14.7 ounces of 950-plus fill versus Zpacks’ 13.7 ounces of 900 fill — and is constructed with a differential cut, while being only $10 more expensive.

The lack of the differential cut was why we weren’t completely happy with this option. In short, bags with a differential cut have the shell cut a couple of inches wider than the liner. This difference in material means that the bag can loft fully even when your elbows, knees, and shoulders press into the liner. We expect premium quilts with high price points to come with this feature. But if they added a differential cut to the Zpacks 20F Full Zip Sleeping Bag, the price would make more sense, and it would really start to compete with our top picks.

Type: Hoodless Sleeping Bag | Advertised Weight: 21 ounces (595 grams) in size standard/medium | Actual Weight: 21.4 ounces (606 grams) | Fill Weight: 13.7 ounces (388 grams) 900 fill water-repellent down | Temperature Rating: 20 degrees Fahrenheit | Packed Size: 6 x 12 inches (15 x 30 centimeters) 7.1 liters

Shop the Zpacks 20F Full Zip Sleeping Bag

Lightest Ultralight Sleeping Bag: Western Mountaineering HighLite ($435)

Pros:

• Impressively warm for the weight
• Very light

Cons:

• Temperature rating limits its versatility

Weighing a mere 16 ounces, the Western Mountaineering HighLite is an incredibly lightweight bag that feels warmer than its 35-degree Fahrenheit rating suggests. It’s perfect for mountain trips when you’re not planning to spend nights high above treeline, but you still want to be able to sleep through relatively chilly nights. It’s also ideal for those spring and fall desert trips when the days are perfect for walking and running, but temperatures drop at night to a point that you don’t want to go with an ultra-ultra lightweight sleep system. The warmth-to-weight ratio of this sleeping bag is what has us returning to it trip after trip. It’s not a viable option for really cold trips, but for the majority of our summer outings, it’s just enough. This sleeping bag has been around for a long time and remains a favorite among the ultralight community.

The shell is made of ExtremeLite fabric and weighs less than an ounce. The 12-denier ripstop fabric is incredibly durable for its weight. The bag employs 850-plus fill ethically sourced goose down, which is some of the lightest and highest-quality down available.

The baffle system is relatively unique, with the horizontal seams sewn completely through. The vertical seams, which make a quilted pattern, are made with strips of netting. This helps keep the down in place while maximizing the loft and, thus, the warmth of the bag.

The half-length #4 YKK zipper is quite small, but we didn’t have any durability issues with it as long as we were careful. In fact, for how light this bag is, we were impressed that after years of use, we didn’t have any issues with the zipper failing, even after countless trips in the Utah desert. The down continued to loft well and stay in place, and we’ve seen people use this bag for well over a decade before finally deciding to replace it … with the exact same bag.

The HighLite comes in three lengths, allowing you to choose the side on which you want the zipper.

Type: Hooded Mummy Bag | Advertised Weight: 16 ounces (453 grams) in 6-foot size | Fill Weight: 9 ounces (255 grams) 850+ fill goose down | Temperature Rating: 35 degrees Fahrenheit | Packed Size: 6 x 12 inches (15 x 30 centimeters) 5.6 liters

Shop the Western Mountaineering HighLite Sleeping Bag

Lightest Ultralight Sleeping Bag — Runner-Up: Sea to Summit Spark Down Sleeping Bag – 30F ($449)

Pros:

• The baffle pattern optimizes warmth
• Lightweight
• Good draft collar

Cons:

• Not warm enough for high and exposed mountain conditions

Not all trips require a 20-degree sleeping bag, and the Sea to Summit Spark Down Sleeping Bag – 30F is a lightweight option perfect for warmer fastpacking outings. With a 30-degree Fahrenheit rating, this bag is adequate for many mountain trips when you’re not planning on spending nights in frigid and exposed places. In fact, we chose it for a six-day traverse of Wyoming’s Wind River High Route and ended up too warm on a couple of the nights. We also used this bag for spring and fall desert trips when the days were perfect for travel and night temperatures dipped into the 30s.

Weighing 17.1 ounces (484 grams), this lightweight bag compresses to 2.4 liters, making it small enough to fit into essentially any fastpack. The 9.3 ounces of 850+ fill down provides plenty of warmth for the weight. The down is treated with a PFAS-free hydrophobic treatment to help it maintain its loft even if the feathers get damp. We’ve spent many nights pairing this sleeping bag with a marginally breathable SOL Escape bivy, but we never felt like this bag got soggy.

The 10-denier outer fabric employs a PFAS-free DWR coating, and we found it to be plenty durable as long as we took care of it. The hood and neck area are lined with a draft collar to keep cold air out, and the hood cinches down tightly if you want to burrow as deeply in as possible.

With a combination of horizontal and vertical baffles in different areas, this sleeping bag provides warmth where needed while also saving weight and construction costs. The vertical baffles around the core provide a high level of warmth, while the horizontal baffles around the leg area help save weight and cost less to construct, keeping the sleeping bag’s price reasonable.

This sleeping bag is available in several different temperature ratings. It also comes in a women’s version with extra insulation in areas, like the hips, where women tend to get colder. The women’s-specific bag weighs 584 grams, which is nearly 100 grams more than the men’s version. Our female tester tested the men’s version and found it warm enough for her needs. If you know you tend to sleep a little colder, you might consider getting the women’s-specific bag.

We include this sleeping bag in our Best Ultralight Backpacking Gear guide because of its versatility and lightweight performance.

Type: Mummy | Advertised Weight: 17.4 ounces (493 grams) in size regular | Actual Weight: 17.1 ounces (484 grams) | Fill Weight: 9.3 ounces ( 264 grams) of 850+ fill | Temperature Rating: 30 degrees Fahrenheit | Packed Size: 2.4 liters

Shop the Sea to Summit Spark Down - 30F Sleeping Bag

Best Ultralight Quilt: Katabatic Gear Alsek 22F Quilt ($379)

Pros:

• Very light
• Comfortable
• The tapered mummy shape is thermally efficient
• Adjustable shoulder girth
• Small packed size

Cons:

• Fiddling with sleeping pad attachment straps isn’t for everyone

The Katabatic Gear Alsek 22F Quilt is an amazingly light and warm quilt with well-thought-out features. It weighs 23.7 ounces in a regular size and is packed with 14.1 ounces of 900-fill goose down. It also has the most secure sleeping pad attachment system we’ve seen on any quilt.

While an older version of this quilt was a bit too narrow for one of our testers, Katabatic Gear has revamped it with wider dimensions to increase comfort and reduce the possibility of drafts. Narrower quilts are more prone to drafts by default. The brand widened the shoulder circumference from 52 inches to 54 inches. This may not sound like a lot, but it’s enough to make a noticeable difference for our 5-foot-11-inch, 155-pound tester.

Due to their shape and size, several sleeping bags on our list suffer from inherent inflexibility, often fitting certain bodies better than others. Because this one has an adjustable girth, we found it to fit a wider range of body types better than any other sleeping bag on this list, from those with very narrow shoulders to those with very broad shoulders. The quilt narrows to 54 inches and widens to an effective width of around 66 inches while still sealing in body heat.

While all zipperless quilts are prone to being drafty, this one reduces the risk with several unique design features. This quilt’s differential cut gives it a permanent tube shape, rather than a blanket shape, so it always looks like it wants to hug you.

The elastic-hemmed edges seem biased to snug under the body rather than spill out over the edges of your pad. The pad attachment system utilizes a static cord, so it doesn’t stretch when you toss and turn at night. We had no issues with drafts when using this bag.

We have nothing but good things to say about the updated version of this quilt. It is warm and comfortable across various temperatures, adjustable for climate control, and can fit different body sizes.

Type: Quilt | Advertised Weight: 22.2 ounces (629 grams) in size regular | Actual Weight: 23.7 ounces (671 grams) | Fill Weight: 14.1 ounces (400 grams) of 900 fill | Temperature Rating: 22 degrees Fahrenheit | Packed Size: 6.5 x 11.5 inches (16.5 x 29.2 centimeters), 6.5 liters

Shop the Katabatic Gear Alsek 22F Quilt

Best Ultralight Quilt — Runner-Up: Enlightened Equipment Convert Sleeping Quilt – 20 Degree ($415)

Pros:

• Lower price point
• Warm and comfortable
• It can work as a blanket as well

Cons:

• Egg shape is less thermally efficient

The Enlightened Equipment Convert Sleeping Quilt – 20 Degree is a very comfortable, reasonably priced, and versatile quilt. The stock model features a 10-denier shell and liner. The size Regular/Regular weighs 27.2 ounces and is filled with 17.9-ounce, 850-fill water-repellent goose down. This same quilt comes in a 950-fill option with 0 to 50 degrees Fahrenheit temperature ratings. We selected the 20-degree rating and down quality that most closely matched the other quilts on our list.

This is one of only two sleeping bags on this list with a drawstring footbox closure — the Feathered Friends Flicker 20 Quilt Sleeping Bag — 20 Degree, reviewed above, being the other. These quilts can be fully opened into blankets for warmer nights or cinched and zipped closed for colder nights. On really warm nights, you can unzip this quilt completely and drape it over your body for a cooler sleeping experience.

The foot cinch doesn’t close as securely as the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree, and it’s the possible culprit for the cold feet one of our testers experienced during one 20-degree Fahrenheit night in the Wasatch Mountains in early May. Because the fully open bag is more or less rectangular, it transforms into an egg-shaped, rather than mummy-shaped, tube when zipped. This leaves a lot of room around the legs. A few of our testers enjoyed the extra space, but others wished the bag was more mummy-shaped to provide more thermal efficiency.

The sleeping pad attachment straps are stretchy, which we found less effective than the static cord attachments on the Katabatic Gear Alsek 22F Quilt. On the other hand, the wafer clips are easier to use than the little cord lock system on the Katabatic Gear quilt.

The shell and liner materials are concerning, at least in appearance, because they lack ripstop. While they feel thicker than the seven-denier fabrics on the Zpacks 20F Full Zip Sleeping Bag, and could theoretically be more downproof, they probably won’t withstand dog claws or general abuse as well. If a tear begins, it will only get bigger over time. Only time will tell if this is a real issue, but our testers preferred the look and feel of some of the fabrics on other bags that got our highest ratings.

Lastly, this quilt doesn’t have a differential cut, but this is acceptable due to its reasonable price.

Overall, this sleeping bag is a solid choice for those seeking a sleeping bag/quilt hybrid that performs well between 20 and 60 degrees Fahrenheit. If you want versatility without spending extra money on the premium features of our higher-rated bags, definitely check it out.

Type: Hoodless Sleeping Bag/Quilt | Advertised Weight: 26.5 ounces (750 grams) in size regular/regular | Actual Weight: 27.2 ounces (772 grams) | Fill Weight: 17.9 ounces (507 grams) 850 fill water-repellent down | Temperature Rating: 20 degrees Fahrenheit | Packed Size: 6.5 x 12 inches (16.5 x 30.5 centimeters) 8.3 liters

Shop the Enlightened Equipment Convert Sleeping Quilt - 20 Degree

Best Budget Ultralight Quilt: Outdoor Vitals StormLoft Down TopQuilt 15 ($340)

Pros:

• Inexpensive
• Warm

Cons:

• Ineffective sleeping pad attachment straps and flimsy clips

The Outdoor Vitals StormLoft Down TopQuilt 15 made our list primarily because of its reasonable price tag of $340. This quilt is moderately light at 24.5 ounces, constructed from decent materials, including 10-denier shell and liner fabrics, and stuffed with 15 ounces of 800-fill water-repellent duck down. This is an excellent option if you’re just starting fastpacking and want a quilt that provides great value for the cost.

We chose this quilt with a temperature rating of 15 degrees Fahrenheit, but were skeptical that this rating was realistic. With only 15 ounces of water-resistant 800-fill duck down inside, we didn’t think it could be as warm as other bags with more and higher-quality down, and our testing proved our suspicions correct. But in the end, that’s all right with us, though, as this quilt has an incredible price tag!

This quilt’s legs and footbox appear loftier than the torso area, which isn’t necessarily bad because it’s easier to add an extra layer to your upper body than to your legs if needed. One of our testers got chilly in the high desert when temperatures plunged unexpectedly to the high 30s after a storm passed, but she warmed up after putting on her down puffy jacket. Other testers found the quilt plenty warm to about 35 degrees while wearing only base layers and a warm hat.

The quilt’s stretchy pad attachment straps don’t slide easily through the wafer clips, making them nearly impossible to adjust. One of our testers broke a clip while adjusting the straps, making the quilt more susceptible to drafts during one cold night in the San Juans of Colorado. Fortunately, she could simply tuck the edge under her body and slept all night comfortably.

That said, don’t think twice about the shortcomings of this quilt if you can’t spend a ton of money on a premium quilt — it’s good enough for most situations. And sometimes — dare we say usually — good enough is all anyone ever needs. Given that the price of entry into fastpacking gear can be steep, we highly recommend this quilt to those interested in fastpacking.

Type: Quilt | Advertised Weight: 23 ounces (652 grams) in size regular | Actual Weight: 24.5 ounces (695 grams) with pad attachment straps | Fill Weight: 16.2 ounces (460 grams) of 800-fill water-repellent down | Temperature Rating: 15 degrees Fahrenheit | Packed Size: 7 x 12 inches (17.8 x 30.5 centimeters) 9.6 liters

Shop the Outdoor Vitals StormLoft Down TopQuilt 15

Comparing the Best Ultralight Sleeping Bags

SLEEPING BAG	PRICE	WEIGHT	TEMP RATING	PACKED SIZE
Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree	$629	27 ounces	20 degrees	7 x 12.5 inches
Montbell Seamless Down Hugger 800 #2	$455	22.7 ounces	25 degrees	5.9 x 11.8 inches
Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree	$529	25.8 ounces	20 degrees	7 x 13 inches
Zpacks 20F Full Zip Sleeping Bag	$519	21.4 ounces	20 degrees	6 x 12 inches
Western Mountaineering HighLite	$435	16 ounces	35 degrees	6 x 12 inches
Sea to Summit Spark Down Sleeping Bag – 30F	$449	17.1 ounces	30 degrees	2.4 liters
Katabatic Gear Alsek 22F Quilt	$379	23.7 ounces	22 degrees	6.5 x 11.5 inches
Enlightened Equipment Convert Sleeping Quilt – 20 Degree	$415	27.2 ounces	20 degrees	6.5 x 12 inches
Outdoor Vitals StormLoft Down TopQuilt 15	$340	24.5 ounces	15 degrees	7 x 12 inches

Buyer’s Guide: How to Choose an Ultralight Sleeping Bag or Quilt

Types of Sleeping Bags

There are three primary types of ultralight sleeping bags, with some variation and crossover between the categories. For this guide to the best ultralight sleeping bags, we’ve reviewed hoodless sleeping bags, like the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree, hooded sleeping bags, such as the Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree, and quilts, including the Katabatic Gear Alsek 22F Quilt.

You should choose one of these based on your sleeping style, how you plan to use the rest of your gear in conjunction with your sleep system, and the types of trips you want to take. We hesitate to say there is a best ultralight sleeping bag for back sleepers and one for side sleepers. Instead, we’ll explain how each style should work.

Hooded or Mummy Sleeping Bags

In general, hooded bags like the Montbell Seamless Down Hugger 800 #2, Western Mountaineering HighLite, and Sea to Summit Spark Down Sleeping Bag – 30F should move with you as you toss and turn because your head remains in the hood. Regarding warmth, the primary benefit of hooded bags is that they provide insulation for your head, eliminating the need to wear a beanie or hooded jacket inside.

The issue is that if you want to use your hooded jacket or beanie as part of your sleep system to save weight, you will face some redundancy issues. Some of our testers also like that hooded bags keep your pillow right where you want it, and other testers like the ability to cinch the hood down around their face for added warmth.

Hoodless Sleeping Bags

Hoodless sleeping bags can either move with you or stay stationary because there is no fixed hood. These bags shine in part because they work with whatever layers you may want to bring along.

If you plan to pack a hooded jacket on every trip, you can wear it inside your Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree, effectively tacking a hood onto it. Fastpacking necessitates the implementation of multiple-use items for efficiency and weight savings, which is why many of us here at iRunFar like hoodless bags. Some of our testers —  especially those who tend to sleep cold, or try to get away with too light of a sleeping bag for the conditions — feel like having a hood that they can cinch down over everything but their nose and mouth adds enough extra warmth to justify the weight of a hood and shy away from hoodless sleeping bags.

Quilt-Style Sleeping Bags

When listing the best ultralight sleeping bags, mentioning quilts such as the Katabatic Gear Alsek 22F Quilt and Outdoor Vitals StormLoft Down TopQuilt 15 is important. This sleep system should remain fixed to a sleeping pad, with your body spinning rotisserie-style inside the pad and quilt sandwich. Like hoodless sleeping bags, quilts also work with hooded jackets to reduce gear redundancy.

Quilts have three real benefits. First, they keep weight low by making a sleeping bag “bottomless,” effectively leaving out fabric and down that would normally wrap underneath the body. Second, they increase comfort by making the width of the bag adjustable. Third, they ensure that the top of the bag — the area where condensation and frost will land — never ends up underneath the body, where the moisture could get pushed through the fabric into the down.

The main downside of a quilt is its susceptibility to drafts. Futzing with straps and cords can also be annoying, especially after a long day when all you want to do is sleep.

Weight

We capped the upper weight of sleeping bags at 29 ounces in this guide because fastpacking requires lightweight sleeping bags. In general, lighter sleeping bags compress small enough to fit in a 25-liter pack, making running more enjoyable. The lightest bag on our list is the Western Mountaineering HighLite, which weighs 16.0 ounces. However, the best ultralight sleeping bag must also be warm, and finding the right balance between weight and warmth is always the ultimate challenge. The Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree, our favorite overall hooded sleeping bag is also the heaviest on the list. However, at 27 ounces, it’s still light enough to be part of a fastpacking kit that allows you to run on various types of terrain, as long as you streamline the rest of your gear. If you’re only going to own one sleeping bag, we recommend investing in one that is at the lower end of the temperature range that you’re going to camp in, even if it’s a bit heavier.

To learn more about fastpacks that can easily carry any sleeping bag in this guide, you can check out our Best Fastpacking Packs guide.

Warmth

After narrowing our list to only bags under 29 ounces, we identified the ones with enough fill to theoretically be warm at or below about 25 degrees Fahrenheit on an insulated sleeping pad. In most cases, we chose 20-degree bags with fill weights ranging from 12 to 16 ounces, depending on the down quality, but some other claimed temperature ratings made it onto the list. So, before even considering the cost or features, we compiled a list of theoretically lightweight and warm sleeping bags.

That left us mostly with pretty expensive bags, such as the insanely warm Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree. Lighter bags, by default, use the highest-quality down, which is one reason they are more costly than heavier bags. Exceptions to this rule are the budget options we found, such as the Outdoor Vitals StormLoft Down TopQuilt 15. This quilt utilizes mid-grade down and ultralight shell materials with minimal features and the simplest design. It’s also pretty warm for what it is.

We also tested a handful of warmer-weather bags, like the 35-degree Western Mountaineering HighLite and the 30-degree Sea to Summit Spark Down Sleeping Bag – 30F, for situations where you don’t need a 20-degree bag to stay warm and want to save some weight in your pack.

Insulation Material

The two primary insulation materials in sleeping bags are down and synthetic. Down comes from either ducks or geese. Synthetic insulation, such as Climashield Apex, is continuous filament insulation, meaning it is manufactured in large sheets and requires no quilting for construction. People choose synthetic-fill sleeping bags for exceptionally wet climates because they keep you warm even when damp. Some sleeping bags, such as the Katabatic Gear Alsek 22F Quilt, have different insulation material options.

A greater amount of synthetic insulation is generally required to achieve the same warmth as a high-grade downfill, so we didn’t test any synthetic sleeping bags. Synthetic insulation also doesn’t pack down quite as small as down and doesn’t spring back from compression as well, meaning it has a shorter lifespan. We recommend down sleeping bags over synthetic ones for nearly any fastpacking situation in dry climates.

Down Fill Power or Loft

Fill power measures the “poofiness” or lofting ability of goose or duck down, which is one of the primary insulation materials in sleeping bags. Lofting is the capability of down clusters to trap air. The higher the grade of down, the loftier it will be, and the more air — and thus body heat — it will trap.

Fill power is measured by placing 30 grams — or about one ounce — of down in a plexiglass cylinder and then adding weight. Higher grades of down compress less under the weight than lower grades.

To use a real-world example, a sleeping bag with 15 ounces of 800-fill down will be less lofty and, therefore, less warm than one with 15 ounces of 950-plus-fill down. To reach the same loft and warmth as the 950-plus-fill sleeping bag, the one with 800 fill would need several more ounces of down, making it heavier.

The only downside to high-loft down is its high price tag. The Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree has 16.8 ounces of 950-plus-fill down and is the highest-priced bag on our list, at $629.

When shopping for a sleeping bag, we recommend looking for one with as high a loft rating as your budget allows. This will ensure a warmer sleeping experience at a lower weight.

Responsible Down Standard (RDS) Certification

Textile Exchange states, “The Responsible Down Standard (RDS) aims to ensure that down and feathers come from animals that have not been subjected to any unnecessary harm.” Every sleeping bag on this list uses RDS-certified down, and we wouldn’t have chosen any of them if they didn’t. The Katabatic Gear Alsek 22F Quilt comes with both goose-down and duck-down options.

Versatility

Versatility in fastpacking gear enables you to use a single item for multiple purposes. The Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree is probably the most versatile bag on this list because it is light and warm and can open at the foot or work as a blanket in warmer weather.

This can be nice if you only want to own one bag and know your trips will take you through mountains and deserts in all seasons. That said, it’s overkill for some situations where a lighter bag, like the Western Mountaineering HighLite, will keep you plenty warm and save you a significant amount of weight in your pack.

Tube-style bags, like the Sea to Summit Spark Down Sleeping Bag – 30F, can be less versatile than hoodless zippered bags or quilts because they have fewer venting options. Also, if you’re carrying a jacket with a hood or a warm hat, you may not need a hood on your sleeping bag.

Durability

Many of this guide’s best ultralight sleeping bags utilize ultralight shell materials that sometimes appear scarily thin. The seven-denier shell on the Zpacks 20F Full Zip Sleeping Bag is an example of a shell material you should treat carefully. That said, not all shell materials are created equal, and it’s possible that the Zpacks’ seven-denier shell could outlast 10-denier or 15-denier materials on some cheaper bags.

We have seen seven-denier material withstand dog paws traveling across them without damage, while the same paws went through the 10-denier material of a different bag like butter. The latter bag’s main issue was a lack of ripstop within the fabric. Ripstop is a woven fabric with a grid of stronger reinforcement fibers to make it more resistant to ripping.

Choose a sleeping bag fabric with a ripstop, no matter the denier. The Enlightened Equipment Convert Sleeping Quilt – 20 Degree lacks ripstop in its material, which raises concerns about its durability.

Sleeping bag durability includes both the shell material and the quality of the down. Higher grades of down, such as the 950-plus fill found on the Feathered Friends sleeping bags, will generally continue lofting longer than the 800 fill found on the Outdoor Vitals StormLoft Down TopQuilt 15. It’s essential to store your sleeping bag uncompressed and as lofted as possible to preserve the down and prevent premature clumping.

Zippers are another point of failure on a sleeping bag, as sand can work its way into the coil and either jam or wear down the sliders. Generally, a larger coil will last longer than a smaller one. We recommend sleeping bags with #5 coil zippers, such as the Zpacks 20F Full Zip Sleeping Bag, over bags with #3 zippers, like the Enlightened Equipment Convert Sleeping Quilt – 20 Degree, for the sake of durability.

Packed Size

Every sleeping bag on this list features an ultralight shell, liner materials, and high-quality down for excellent packability. The smallest-packing sleeping bag on our list is the Western Mountaineering HighLite, measuring 6 x 12 inches when packed. This bag takes up very little space, fitting easily inside even a tiny fastpacking pack such as the Pa’lante Packs Joey — read our Pa’lante Packs Joey review or check out more fastpack options in our Best Fastpacking Packs guide. A sleeping bag is likely the largest volume item in a fastpack, so you’ll want to consider it carefully when assembling a fastpacking kit. If you want to fit everything into a 25-liter pack, you’ll need a more packable sleeping bag than if you’re using a 30-liter or larger pack.

Why You Should Trust Us

The iRunFar team has been fastpacking for over a decade and has watched this adventure niche grow. What started as two separate endeavors — ultralight backpacking and adventure running — have now merged into one: fastpacking.

For many of us, a good night’s rest is critical for completing the next day’s miles. We frequently have no idea where we’ll end up for the night — parked on the edge of a snowfield at 13,000 feet or cowboy camping below the cold, cloudless firmament — so we want to haul along a sleeping bag that will perform wherever we lay down.

While a couple of fastpacking-appropriate sleeping bags have been in the iRunFar team’s rotation for a few years, for this guide, we set out to research dozens and test 15 of what we thought could be the best sleeping bags for three-season fastpacking and ultralight backpacking.

We rated the bags on their warmth, shape, comfort, and weight, carefully examining the quality and quantity of down in each. Since the initial publication of this guide, we have continued to add new sleeping bags to our rotation, providing you with the best ultralight sleeping bag options on the market.

We tested sleeping bags on adventures in Silverton, Colorado; the Wasatch Mountains of northern Utah; the Mazatzal Mountains of central Arizona; and various locations throughout the canyon country of the Colorado Plateau. Some of our team members also head to New Zealand regularly to test gear in a completely different climate. For this guide, a team of fastpackers with a wide range of body types tested these ultralight sleeping bags in various temperatures and environmental conditions to help you determine which bag will work best for you.

Frequently Asked Questions About Ultralight Sleeping Bags and Quilts

What fill power is best for a fastpacking sleeping bag?

This is one of the very few areas where there’s a pretty simple answer that doesn’t require much nuance. Higher fill-power sleeping bags, like the Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree, are lighter, warmer for their weight, and will last longer than lower fill-power sleeping bags. The only downside is the higher cost.

However, this is one area where we’d recommend spending some cash. A good sleeping bag filled with quality down will easily last 20 years if you take care of it. The Feathered Friends sleeping bags utilize the highest-grade down of any on our list. The Outdoor Vitals StormLoft Down TopQuilt 15 uses lower-quality down, but it’s also the lowest-cost sleeping bag in this guide.

How should my sleeping bag or quilt fit?

Fit is somewhat subjective so that we won’t give you any absolutes here. When shopping for a fastpacking sleeping bag, remember that narrower bags are generally more thermally efficient, meaning they’ll be warmer for their weight than wider sleeping bags. Wider sleeping bags create a lot of air space between your body and the bag, sometimes making it difficult to warm up.

Mummy bags like the Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree and Western Mountaineering HighLite will be more thermally efficient than the egg-shaped Enlightened Equipment Convert Sleeping Quilt – 20 Degree.

If you can’t stand narrowness and prefer wider bags for comfort, consider quilts, as their shoulder circumference is adjustable. You can widen the shoulder girth of the Katabatic Gear Alsek 22F Quilt to a measurement of around 66 inches and narrow it to 54 inches. Additionally, you can buy most sleeping bags on this list in different widths and lengths.

Do I need water-resistant down?

Some of the sleeping bags on our list, including the Outdoor Vitals StormLoft Down TopQuilt 15 and the Sea to Summit Spark Down Sleeping Bag – 30F, have hydrophobic or water-repellent down. This means the brand treated the down clusters with a durable water-repellent (DWR) chemical coating. Third-party tests show that this treatment indeed increases the down’s water resistance. However, it is unclear how long this treatment will last or if it affects the down’s long-term lofting ability. Some major brands, such as Western Mountaineering and Feathered Friends, don’t use treated down. But if you want extra peace of mind during fastpacking adventures in a wet climate, choosing a bag with hydrophobic down probably couldn’t hurt. Sometimes, especially if you’re sleeping in a bivy or a single-wall tent, it’s nearly impossible to wake up with a completely dry sleeping bag. In this case, it’s often a good idea to dry a down sleeping bag out during a lunch stop to ensure the down can stay as dry as possible throughout a longer trip.

If you consistently fastpack in wet or humid climates, you might want to consider a synthetic sleeping bag. Synthetic fill will remain warm even if wet, while down will lose its insulating properties as it gets damp and the down feathers start to clump together. Synthetic insulation has a lower warmth-to-weight ratio compared to down, so you’ll need to carry a heavier bag to achieve the same level of warmth.

These sleeping bags are expensive! Do I really need to spend $400 or more on a sleeping bag?

The four most expensive items in a fastpacking kit are the fastpack, sleeping pad, tent, and sleeping bag. However, excellent budget options are available in every category except sleeping bags. You can find $150 packs, $50 pads, and $100 tarps, but sleeping bags are different. The cheapest bag on our list is still $340!

However, because a high-quality sleeping bag can last 20 years, we recommend saving for a good one. With this in mind, we chose our top pick, the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree. At $529, it’s undoubtedly expensive, but if you take care of it, it will continue to perform well in virtually any fastpacking scenario for a long time.

If a $500 sleeping bag makes it 20 years, that’s only $25 a year. That said, the Outdoor Vitals StormLoft Down TopQuilt 15 is a reasonable option for nearly half the price.

Should my sleeping bag be constructed with a differential cut?

Most high-end sleeping bags and quilts are constructed with a differential cut, meaning the inside is smaller than the outside. This makes it more difficult for a jutting elbow or knee to compress the insulation, and therefore helps prevent cold spots. Constructing a bag with a differential cut is a little more time-consuming than sewing two pieces of equally sized fabric together, so these bags are usually more expensive. The Katabatic Gear Alsek 22F Quilt and Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree both feature a differential cut, and both are among the more expensive bags in this guide.

We don’t think a sleeping bag’s differential cut is mandatory. Not having one saves money, making bags like the Outdoor Vitals StormLoft Down TopQuilt 15 available to more people. In our experience, the bags on this list without a differential cut are still very warm.

Should I get a down or synthetic sleeping bag?

High-quality down sleeping bags are warmer for the weight than similarly rated synthetic sleeping bags, prompting us to choose them for most fastpacking trips. Down insulation also compresses smaller than synthetic insulation and bounces back from compression better than synthetic, giving it a longer lifespan. The primary benefit of synthetic sleeping bags is that they retain their warmth even when wet.

Some sleeping bags, such as the Outdoor Vitals StormLoft Down TopQuilt 15 and Sea to Summit Spark Down Sleeping Bag – 30F, have down treated with a water-repellent coating that helps keep it warmer when damp. People who try to avoid using animal products may also prefer to opt for a synthetic sleeping bag.

What is the difference between a sleeping bag and a quilt? Should I get a sleeping bag or a quilt?

The main difference is that sleeping bags fully encapsulate you, whereas quilts are open underneath your body. Choose a sleeping bag like the Western Mountaineering HighLite if you want it to move with you when you toss and turn. Choose a quilt like the Katabatic Gear Alsek 22F Quilt if you want it to remain fixed to your sleeping pad as your body spins inside of it.

Quilts save weight by losing the zipper and the material that would normally be underneath the body. They are also adjustable in width, widening for comfort and snuggling close for thermal efficiency. This adjustability also means that a single quilt could fit a range of body shapes and sizes.

One downside of quilts is that they can be susceptible to drafts. The cordage or webbing used to attach them to your sleeping pad can be a pain to fiddle with, especially when you’re tired and cold. The clips on the Outdoor Vitals StormLoft Down TopQuilt 15 had durability issues, but we could tuck the quilt underneath us and stay warm.

We recommend sleeping bags for those who don’t want to spend a lot of time setting up their sleep system. You just get in it and pass out. Quilts have a bit of a learning curve.

I sleep cold at night. Which sleeping bag should I get?

Instead of looking at temperature ratings, note the amount of down in each sleeping bag you’re trying to choose between. For example, the Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree features 16.8 ounces of 950-plus fill, rated at 20°F. The Outdoor Vitals StormLoft Down TopQuilt 15 has a lower claimed rating — 15 degrees Fahrenheit — but less down and a lower grade of down. In this case, the Swallow will be a far warmer bag than the StormLoft, even if the marketing claims otherwise. Our testing proved this, with all testers agreeing that the Swallow was the warmest bag we tried.

Most sleeping bags come with three different temperature ratings: Comfort, Lower Limit, and Extreme. Companies generally define the comfort temperature as the rating where a “standard” woman will be able to sleep comfortably through the night. We fully acknowledge the shortcomings of this rating system, as different women sleep comfortably at different temperatures, and some sleep as warm or even warmer than men. However, this is the system that has been established. Since women, on average, tend to sleep colder than men for various physiological reasons, this rating is higher than the Lower Limit, which is where a “standard” man can sleep comfortably for eight hours. The extreme rating is defined as the temperature at which a “standard” woman will be able to survive for six hours without the risk of death from hypothermia, but you’ll be shivering for sure.

When choosing a sleeping bag, determine whether you’re a warm or cold sleeper and select one based on how important complete warmth is to you versus saving a bit of weight.

If I sleep hot at night, which sleeping bag should I get? Should I get a quilt?

Most sleeping bags on our list come in different temperature ratings. Our top pick, the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree, is also available in 30- and 40-degree Fahrenheit ratings for those who sleep hot.

If you sleep hot at night, we would recommend getting a sleeping bag or quilt with a full-length zipper and a drawstring footbox, such as the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree or the Enlightened Equipment Convert Sleeping Quilt – 20 Degree. These bags provide more venting options than any others on our list. If you get too hot, you can uncinch the drawstring, poke your feet out, or unzip the entire thing and drape it over you like a blanket.

Some quilts are better for hot sleepers than others. The Katabatic Gear Alsek 22F Quilt doesn’t vent as well as the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree because it doesn’t unzip all the way or open at the feet.

My feet get cold at night, so which sleeping bag would be best for me?

Many people struggle with cold feet at night, even if they bring a second set of warm socks for sleeping. Cold feet can quickly ruin an excellent night of camping.

If you can maintain a warm core but still have numb feet, the best ultralight sleeping bag for you is probably not a quilt or sleeping bag with a zipper down to the feet, like the Enlightened Equipment Convert Sleeping Quilt – 20 Degree. Instead, you should aim for a bag like the Feathered Friends Swallow UL 20/30 Sleeping Bag – 20 Degree, which completely protects your feet from the elements. Our tester, who suffers from chronically cold feet, also highly recommends bringing a pair of down booties to sleep in.

How should I take care of my sleeping bag? How do I wash my sleeping bag?

You can take several steps to extend the life expectancy and functionality of your sleeping bag.

• Sleep in base layers or a sleeping bag liner to prevent skin oils from soaking into the sleeping bag and degrading the down.
• Don’t compress your sleeping bag longer than necessary. Too much compression can reduce the lofting ability of down.
• Store your sleeping bag hanging or in a large, breathable storage bag, allowing it to loft as much as possible. If you plan to hang your sleeping bag, do so in a closet with a closed door. As one of our testers tragically discovered, cats love to climb sleeping bags.
• Wash your sleeping bag by hand or in a front-loading washer on a gentle cycle. Use soap made for washing down-filled items, such as Nikwax Down Wash Direct. Rinse at least twice to ensure all the soap is removed. Set the drier to low and tumble it with three tennis balls to break up clumping down clusters.

With proper care, a high-end sleeping bag like the Feathered Friends Flicker UL Quilt Sleeping Bag – 20 Degree can last a very long time. Investing in the best ultralight sleeping bag your budget allows for and taking care of it can make it worth the price.

I ripped a hole in my sleeping bag. What do I do?

We recommend carrying stick-on patches on your fastpacking trips to field-repair sleeping bag holes. A single sheet of Tear Aid Type A should be plenty. First, cut the patch to cover the tear completely and round the corners so it won’t peel. Then, clean any dirt away from the tear with water or alcohol and let it dry completely. Peel the backing from the patch and press it firmly over the tear.

A Tear Aid patch may last for a long time, but it probably won’t withstand multiple laundry cycles. If the tear is large, contact the manufacturer to see if they will sew a more permanent patch over it.

A sleeping bag like the Outdoor Vitals StormLoft Down TopQuilt 15, with its 10-denier liner and shell, will be more resistant to tears and scuffs than some extremely ultralight bags. Thinner fabrics with ripstop, such as those on the Zpacks 20F Full Zip Sleeping Bag and Western Mountaineering HighLite, can be both incredibly thin and durable.

Call for Comments

• Do you prefer sleeping bags or quilts?
• How low have you pushed a 20-degree sleeping bag?
• What’s your favorite layering system for sleeping?

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