A fastpacking trip could begin where a snowmelt river runs out into a warm, sunlit meadow, but we fastpackers move quickly, so evening may find us well above treeline where it’s chilly, even in the summer. So when it comes to a sleeping system, we want to carry an ultralight sleeping bag or quilt that feels weightless when moving and warm and cozy in camp.
An ideal ultralight sleeping bag or quilt for fastpacking will compress down small enough to fit in a fastpack, and it will be light enough that most people can comfortably run with it. It will also be comfortable to sleep in throughout a wide range of temperatures because, as most fastpackers and ultralight backpackers know, the wilds are capricious.
This year we researched dozens of ultralight sleeping bags and quilts, tested 14 of them, and chose eight for this list. The sleeping bags that made the cut are all light, warm, durable, comfortable, and packable.
Below are our favorite fastpacking sleeping bags of 2023. 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, and best ultralight sleeping pads guides as well!
Use these links to skip quickly to the kinds of sleeping bags and quilts you’d like to learn more about:
- Best Hoodless Ultralight Sleeping Bag: Feathered Friends Flicker UL 20 Quilt Sleeping Bag
- Best Hooded Ultralight Sleeping Bag: Feathered Friends Swallow UL 20 Sleeping Bag
- Best Ultralight Quilt: Katabatic Gear Alsek 22F Quilt
- Lightest Ultralight Sleeping Bag: Feathered Friends Tanager 20 CFL Sleeping Bag
- Best Budget Hooded Ultralight Sleeping Bag: REI Co-op Magma 15 Sleeping Bag – Men’s
- Best Budget Ultralight Quilt: Outdoor Vitals StormLoft Down TopQuilt 15
- Honorable Mention Ultralight Sleeping Bag: Zpacks 20F Full Zip Sleeping Bag
- Honorable Mention Ultralight Sleeping Quilt: Enlightened Equipment Convert 20 Quilt Sleeping Bag
Best Hoodless Ultralight Sleeping Bag: Feathered Friends Flicker UL 20 Quilt Sleeping Bag ($489)
Our testers agree that the Feathered Friends Flicker UL 20 Quilt Sleeping Bag can be used comfortably throughout a wider range of temperatures than any other sleeping bag on this list, prompting us to name it the best hoodless sleeping bag for fastpacking.
As this sleeping bag is hoodless, it is designed to be used in conjunction with a hooded jacket or warm hat. Its full-length zipper and drawstring footbox closure provide ample venting options. This bag can even be opened up into a blanket for warmer nights. It is also astonishingly light and packable, stuffed full of 14.7 ounces of 950-plus fill down and weighing only 25.8 ounces in a size regular on our scale.
We found this sleeping bag to be warmest and most comfortable if 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. This was comfortable and warm between about 27 and 45 degrees Fahrenheit.
Below about 25 Fahrenheit, we’d recommend zipping up the sleeping bag all the way but keeping the zipper under the body because, even though it has a draft tube, zippers tend to be a cold spot in most bags. This zipper’s low profile makes it virtually imperceptible when laying on it.
When fully zipped, the shape is mummy-like for thermal efficiency, snugging in around the legs. The Enlightened Equipment Convert 20 Quilt Sleeping Bag, by contrast, is more egg-shaped, a probable reason it wasn’t as warm as this sleeping bag.
This sleeping bag is nearly perfect but we did find one problem with it. 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 are not sufficient for holding the neck opening closed, and even small movements uncinch the opening. We added an additional cord lock to each shock cord to remediate this issue.
The Feathered Friends Flicker UL 20 Quilt Sleeping Bag’s versatility is truly outstanding, making it our recommendation for anyone wanting only one sleeping bag. It’s cozy well into the teens Fahrenheit, super light for how warm it is, vents easily, and can be draped blanket style for warmer nights.
Be sure to read our in-depth Feathered Friends Flicker UL 20 Quilt Sleeping Bag review, too!
Type: Hoodless Sleeping Bag/Quilt
Advertised Weight: 25.2 ounces (715g) in a size regular
Actual Weight: 25.8 ounces (731g)
Fill Weight: 14.7 ounces (417g) of 950-plus fill
Temperature Rating: 20 degrees Fahrenheit
Packed Size: 7 x 13 inches (17.8 x 33cm), 8 liters
- Very light
- Conservative temperature rating
- Tapered mummy shape is thermally efficient
- Opens into blanket
Best Hooded Ultralight Sleeping Bag: Feathered Friends Swallow UL 20 Sleeping Bag ($589)
The Feathered Friends Swallow UL 20 Sleeping Bag is the warmest sleeping bag we tested that is still light enough — 27 ounces — to qualify as a fastpacking sleeping bag. It is constructed from light, durable, and downproof fabrics and crammed full of 16.8 ounces of 950-plus fill down.
We slept in this sleeping bag on several fastpacking trips in temperatures ranging between 22 and 45 degrees Fahrenheit. It was clear that even at 22 Fahrenheit, we were not approaching this bag’s limit. It’s warm. There is no real draft collar, forcing you to cinch the opening snugly around your face in temperatures below freezing. If this bag had a draft collar, you could leave the opening mostly uncinched, which would be more comfortable, in our opinion.
Several of our women testers were happy with the 60-inch shoulder width of this sleeping bag. They found it to be more thermally efficient than the 63-inch shoulder width of the REI Co-op Magma 15 Sleeping Bag – Men’s. For this reason, we believe that the Feathered Friends Swallow UL 20 Sleeping Bag is a truly unisex sleeping bag, fitting a range of bodies better than other wider and narrower bags. It’s also just insanely warm. If you can afford the high price tag, you won’t be disappointed.
Type: Hooded Mummy Bag
Advertised Weight: 27 ounces (766g) in a size regular
Actual Weight: 26.95 ounces (764g)
Fill Weight: 16.8 ounces (476g) of 950-plus fill
Temperature Rating: 20 degrees Fahrenheit
Packed Size: 7 x 12.5 inches (17.8 x 31.75cm), 9 liters
- Extremely warm
- Dimensions fit all testers well
- Minimal draft collar
Best Ultralight Quilt: Katabatic Gear Alsek 22F Quilt ($425)
The Katabatic Gear Alsek 22F Quilt is an amazingly light and warm quilt with well-thought-out features. It weighs a total of 23.7 ounces in a size regular 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.
One of our testers used an older version of this quilt for nearly five years before deciding it was just a little too narrow. To our pleasant surprise, Katabatic Gear has revamped it this year with new wider dimensions to increase comfort and reduce the possibility of drafts. Narrower quilts by default are more prone to drafts. This quilt used to have a shoulder girth of 52 inches and it has been widened to 54 inches. This may not sound like a lot, but it’s enough to make a difference for our 5-foot, 11-inch and 155-pound tester.
Several sleeping bags in our list suffer from inherent inflexibility due to their shape and size, often fitting certain bodies and not others. Because this one has an adjustable girth, we found it to fit a wider array of bodies better than any other sleeping bag on this list, from very narrow-shouldered to very broad-shouldered people. Indeed, it can be narrowed to only 54 inches and widened to an effective width of around 66 inches, all while still sealing in body heat.
All zipperless quilts are at risk of becoming drafty, but this one mitigates the risk well through several means. This quilt’s differential cut gives it a permanent tube shape rather than a blanket shape, so it always looks like it wants to give you a hug. The elastic-hemmed edges seem biased to snug under the body rather than spill out over the edges of your pad. And the pad attachment system utilizes a static cord, so it doesn’t stretch when you toss and turn in the 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 throughout a vast range of temperatures and can be adjusted both for climate control and to fit different body sizes. The Katabatic Gear Alsek 22F Quilt is the best quilt for fastpacking we’ve found.
Advertised Weight: 22.2 ounces (629g) in a size regular
Actual Weight: 23.7 ounces (671g)
Fill Weight: 14.1 ounces (400g) of 900 fill
Temperature Rating: 22 degrees Fahrenheit
Packed Size: 6.5 X 11.5 inches (16.5 x 29.2cm), 6.5 liters
- Very light
- Tapered mummy shape is thermally efficient
- Adjustable shoulder girth
- Small packed size
- Fiddling with sleeping pad attachment straps isn’t for everyone
Lightest Ultralight Sleeping Bag: Feathered Friends Tanager 20 CFL Sleeping Bag ($449)
One of our testers has used the Feathered Friends Tanager 20 CFL Sleeping Bag as his go-to fastpacking sleeping bag for over a year, primarily because of its impressive warmth-to-weight ratio. For only 20.2 ounces in the 74-inch length, you get a bag stuffed with 13.3 ounces of 950-plus fill down that can take you to 20 degrees Fahrenheit or lower comfortably. It’s also the lightest sleeping bag in this buyer’s guide.
To save weight, Feathered Friends gave this bag a 5- x 7-denier nylon shell. This shell is scary light in both appearance and feel but has held up to stuffing, unstuffing, and the unavoidable claws of a dog just fine. It’s also far more downproof than any other 7-denier shell material we’ve come across.
Being a zipperless, tube-style sleeping bag, it is not for everyone. The claustrophobic among us might shudder at the idea of sliding a sleeping bag on like a sock. The 62-inch shoulder girth was both comfortable and thermally efficient for our slim to average male testers, but a little wide for our smaller female testers — unless they were layering with additional clothing, in which case this bag worked well.
This bag also has a pretty extreme taper, so the leg area is quite narrow. We found this to be somewhat uncomfortable after long days when our joints were feeling tight and our legs wanted to bend and stretch. On the other hand, we were grateful for the efficient cut of this bag during colder nights because the down wrapped warmly around our legs.
The upper end of this bag’s comfort zone is probably about 45 degrees Fahrenheit, when we just leave the neck opening completely uncinched. One of our testers slept this way three nights in a row during a fastpacking trip through the mountains and deserts of central Arizona. If you want a bag to be comfortable throughout a greater range of temperatures, look at a sleeping bag with better venting options such as the Feathered Friends Flicker UL 20 Quilt Sleeping Bag, which is about as warm but will also be comfortable in warmer temperatures in blanket mode.
In our experience, the lower end of this bag’s comfort is about 14 degrees Fahrenheit when wearing base layers and a down hood and sleeping on an insulated pad. This is astounding considering the Feathered Friends Tanager CFL 20 Sleeping Bag is the lightest on our list.
Type: Hoodless Zipperless Sleeping Bag
Advertised Weight: 19.7 ounces (558g) in a size regular
Actual Weight: 20.2 ounces (573g)
Fill Weight: 13.3 (377g) ounces of 950-plus fill
Temperature Rating: 20 degrees Fahrenheit
Packed Size: 5.5 x 11 inches (14 x 28cm), 6 liters
- Crazy light
- Excellent warmth-to-weight ratio
- Tapered mummy shape is thermally efficient
- Tiny packed size
- Pulling a sleeping bag on like a sock isn’t for everyone
- Minimal venting options
Best Budget Hooded Ultralight Sleeping Bag: REI Co-op Magma 15 Sleeping Bag – Men’s ($399)
The REI Co-op Magma 15 Sleeping Bag – Men’s surprised us more than any other sleeping bag we tested. For only $399, you get an exceptionally warm mummy bag with well-designed features and premium-grade materials. This bag is often 30% off during REI’s sales, making it only $280, and we don’t think you can find a better mummy bag cheaper than that.
In a size regular, this sleeping bag has 15.9 ounces of water-resistant 850 fill down inside it and weighs a total of 27.4 ounces. These specs compete very directly with the other hooded mummy bag on our list, the Feathered Friends Swallow UL 20 Sleeping Bag, but costs $190 less, making it an easy choice for most people.
This sleeping bag went with us on several trips through Capitol Reef National Park in southern Utah and the Wasatch Mountains of northern Utah, where it kept our testers warm in temperatures ranging between 25 and 45 degrees Fahrenheit. We agreed that the 15-denier liner and shell material was comfortable and durable, the zipper slid smoothly, and the partial draft collar effectively prevented body heat from escaping.
We did not test the women’s version of this bag because it has so much down in it that it probably qualifies as a winter sleeping bag and, at 36 ounces, is too heavy for this list. Unfortunately, the men’s version was a little too wide for our women testers at 63 inches in the shoulders.
We wish REI would split the difference between the men’s and women’s bags, making a 60-inch shoulder-width unisex sleeping bag with a total weight of about 28 ounces. In our opinion, that would suit a wider range of bodies and needs better than their current options.
Type: Hooded Mummy Bag
Advertised Weight: 28.2 ounces (800g) in a size regular
Actual Weight: 27.4 ounces (776g)
Fill Weight: 15.9 ounces (451g) of 850 fill
Temperature Rating: 16 degrees Fahrenheit
Packed Size: 7.5 x 15 inches (19 x 38.1cm), 10.9 liters
- Shoulder width a bit wide for narrower people
- Footbox too big for thermal efficiency
- Women’s version too heavy to qualify as a fastpacking sleeping bag
Best Budget Ultralight Quilt: Outdoor Vitals StormLoft Down TopQuilt 15 ($245)
The Outdoor Vitals StormLoft Down TopQuilt 15 made our list primarily because of its reasonable price tag of $245. This quilt is moderately light at 24.5 ounces, is constructed from decent materials including 10-denier shell and liner fabrics, and is stuffed with 15 ounces of 800-fill water-repellent duck down. If you are just getting into fastpacking and don’t want to spend a ton of money, we highly recommend this quilt.
We chose this quilt with a temperature rating of 15 degrees Fahrenheit but were skeptical that this rating was realistic. With 15 ounces of water-resistant 800-fill duck down inside, this quilt is not quite as warm as other bags in this list with similar amounts of a higher grade of down. The Feathered Friends Flicker UL 20 Quilt Sleeping Bag, for example, has 14.7 ounces of 950-plus-fill down in it and is much loftier and warmer. That’s all right with us though as this quilt has an incredible price tag!
The legs and footbox of this quilt appear to be loftier than the torso area, which isn’t necessarily a bad thing because it’s easier to add an extra layer to your upper body than your legs if need be. 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 to be 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 through the wafer clips easily, making them nearly impossible to adjust. Trying to adjust the straps, one of our testers broke a clip, rendering the quilt more susceptible to drafts during one cold night in the San Juans of Colorado. Fortunately, she was able to simply tuck the edge under her body and she slept comfortably all night.
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. Especially if Outdoor Vitals improves the StormLoft Down TopQuilt 15’s sleeping pad attachment system, we’ll continue to recommend it to fastpackers on a budget.
Advertised Weight: 23 ounces (652g) in a size regular
Actual Weight: 24.5 ounces (695g) with pad attachment straps
Fill Weight: 16.2 ounces (460g) of 800 fill water-repellent down
Temperature Rating: 15 degrees Fahrenheit
Packed Size: 7 x 12 inches (17.8 x 30.5cm) 9.6 liters
- Ineffective sleeping pad attachment straps and flimsy clips
Honorable Mention Ultralight Sleeping Bag: Zpacks 20F Full Zip Sleeping Bag ($479)
The Zpacks 20F Full Zip Sleeping Bag is a high-end quilt/sleeping bag hybrid that would be virtually perfect if they made one single revision. Because it lacks a differential cut it should be priced a bit lower. But first the good.
Weighing only 21.4 ounces in a size regular, this is the second lightest bag on our list, right behind the Feathered Friends Tanager CFL 20 Sleeping Bag. It is constructed from premium materials, including 13.7 ounces of 900 fill DownTek goose down and 0.51 ounce/square yard, 7-denier liner and shell fabrics. The fabrics are thin and light, allowing the down to loft fully. The shell is also so thin it’s scary but is constructed with a tiny ripstop woven throughout, providing some peace of mind. Unfortunately, this material has proven to be the least downproof on any bag we tested, with little feathers leaking through here and there.
The bag has a long, two-way zipper so you can 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 to not feel constrictive around the neck. And 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. In our opinion, it’s a little overpriced for what it is, especially when compared to the Feathered Friends Flicker UL 20 Quilt Sleeping Bag. The Feathered Friends bag has more high-quality down — 14.7 ounces of 950-plus fill versus Zpacks’s 13.7 ounces of 900 fill — and is constructed with a differential cut while being only $10 more expensive.
Why is a differential cut important? In short, bags constructed with the shell cut a couple of inches wider than the liner are capable of lofting fully even when elbows, knees, and shoulders are pressing 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 could be justified and it would really start to compete with our top picks.
Type: Hoodless Sleeping Bag
Advertised Weight: 21 ounces (595g) in a size standard/medium
Actual Weight: 21.4 ounces (606g)
Fill Weight: 13.7 ounces (388g) 900 fill water-repellent down
Temperature Rating: 20 degrees Fahrenheit
Packed Size: 6 x 12 inches (15 x 30cm) 7.1 liters
- Very light
- Durable #5 coil zipper
- Expensive for no differential cut
- 7-denier shell material less downproof than others we tested
Honorable Mention Ultralight Quilt: Enlightened Equipment Convert 20 Quilt Sleeping Bag ($400)
The Enlightened Equipment Convert 20 Quilt Sleeping Bag is a very comfortable, reasonably priced, and versatile quilt. The stock model is constructed with a 10-denier shell and liner. The size regular/regular is stuffed full of 17.9-ounce, 850-fill water-repellent goose down and weighs a total of 27.2 ounces. It is possible to order this same quilt in different temperature ratings or stuffed with different grades of down. We chose the rating and down quality that would most closely compare to the other quilts on our list.
This is one of only two sleeping bags on this list that has a drawstring footbox closure — the Feathered Friends Flicker UL 20 Quilt Sleeping Bag being the other. Both of these quilts can be fully opened into blankets for warmer nights or cinched and zipped closed for colder nights. One of our testers appreciated this feature when sleeping on the banks of Lake Powell in 60-degree Fahrenheit nights. In these situations, it is possible to simply drape the quilt over one’s body so that cool air can find its way to your feet or torso.
The foot cinch doesn’t close as securely as the cinch on the Feathered Friends Flicker UL 20 Quilt Sleeping Bag and is 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, and is therefore very roomy in the legs. Some of our testers wished it was more mummy-shaped for thermal efficiency while others liked the comfort of the roomy leg area.
The sleeping pad attachment straps are stretchy, which we found to be less effective than the static cord attachments on the Katabatic Gear Alsek 22F Quilt. The wafer clips, on the other hand, are easier to use than the little cord lock system on the Katabatic Gear quilt.
The shell and liner materials are worrying, in appearance at least — they don’t have ripstop. While they feel thicker than the 7-denier fabrics on the Zpacks 20F Full Zip Sleeping Bag or the Feathered Friends Tanager CFL 20 Sleeping Bag, and could theoretically be more downproof, they probably won’t deal as well with dog claws or general abuse. 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 is not constructed with a differential cut, but this is acceptable considering the reasonable price.
All in all, the Enlightened Equipment Convert 20 Quilt Sleeping Bag is a solid choice for those wanting a sleeping bag/quilt hybrid that will perform well between 20 and 60 degrees Fahrenheit. If you want versatility and don’t want to spend the extra money for the premium features of our higher-rated bags, definitely check it out.
Type: Hoodless Sleeping Bag/Quilt
Advertised Weight: 26.5 oz ounces (750g) in a size regular/regular
Actual Weight: 27.2 ounces (772g)
Fill Weight: 17.9 ounces (507g) 850 fill water-repellent down
Temperature Rating: 20 degrees Fahrenheit
Packed Size: 6.5 x 12 inches (16.5 x 30.5cm) 8.3 liters
- Egg shape less thermally efficient
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. In this list, we’ve reviewed hoodless sleeping bags, hooded sleeping bags, and quilts. You’ll want to 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 do.
We hesitate to say that one type of bag is better for back sleepers and one is better for side sleepers. Instead, we’ll just explain how each of these styles is intended to work.
Hooded or Mummy Sleeping Bags
In general, hooded bags like the REI Co-op Magma 15 Sleeping Bag – Men’s are meant to move with you as you toss and turn because your head remains in the hood. As far as warmth goes, the main benefit of hooded bags is that they provide insulation for your head, meaning you don’t have to wear a beanie or hooded jacket inside.
The issue with this is if you were wanting to use your hooded jacket or beanie as a 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.
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 Tanager 20 CFL Sleeping Bag, for example, 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.
Quilt-Style Sleeping Bags
Quilts such as the Katabatic Gear Alsek 22F Quilt are meant to remain fixed to a sleeping pad, with your body spinning rotisserie-style inside them. They, like hoodless sleeping bags, also work in combination with hooded jackets and the like to reduce gear redundancy.
But, in our opinion, the real benefits of quilts are threefold: 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 would 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.
We put a cap of 29 ounces for sleeping bags in this guide because fastpacking sleeping bags need to be light. In general, lighter sleeping bags will compress small enough to fit in a 25-liter pack and will make for more enjoyable running. The lightest bag on our list is the Feathered Friends Tanager 20 CFL Sleeping Bag with a total weight of 20.2 ounces.
But fastpacking sleeping bags can’t just be light, they have to be warm too.
After narrowing our list to only bags under 29 ounces, we then identified the ones with enough fill in them to theoretically be warm at or below about 25 degrees Fahrenheit on an insulated sleeping pad. In most cases, that meant we were choosing 20-degree bags with between 12 and 16 ounces of fill depending on the grade, but some other claimed temperature ratings made it into the list. So, before even looking at cost or features, we had compiled a list of theoretically light and warm sleeping bags.
For the most part, that left us with pretty expensive bags such as the insanely warm Feathered Friends Swallow UL 20 Sleeping Bag. Lighter bags by default use the highest quality down, which is one of the reasons they are more costly than heavier bags. Exceptions to this rule are the budget options we found such as the Hammock Gear Economy Burrow — which we hope to test next year — and the Outdoor Vitals StormLoft Down TopQuilt 15, which got our budget award. This quilt uses mid-grade down and ultralight shell materials while having minimal features and the simplest design. It’s also pretty warm.
The two main types of insulation materials in sleeping bags are down and synthetic. Down comes from either ducks or geese. Synthetic insulation, such as Climashield Apex, is a 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 it can keep you warm even when damp.
A greater amount of synthetic insulation is generally required to achieve the same warmth as a high-grade down fill, which is the main reason 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.
Down Fill Power or Loft
Fill power measures the poofiness or lofting ability of goose or duck down, one of the main insulation materials in sleeping bags. Lofting can be thought of as 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 placing a weight on top of it. Higher grades of down will compress less under the weight than lower grades.
To move this into a real-world example, this means that a sleeping bag with 15 ounces of 800-fill down will be less lofty and therefore less warm than a sleeping bag with 15 ounces of 950-plus-fill down. To reach the same loft and warmth as that 950-plus-fill sleeping bag, the one with 800 fill would need several more ounces of down in it, making it heavier.
The only downside to high-loft down is its high price tag.
When shopping for a sleeping bag, we recommend looking for a sleeping bag with as high a loft rating as your wallet can afford, as this means you’ll be getting a warmer sleeping experience at a lower weight.
Responsible Down Standard (RDS) Certification
According to Textile Exchange, “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.
Versatility in fastpacking gear allows you to use single items in multiple conditions. The Feathered Friends Flicker UL 20 Quilt Sleeping Bag is probably the most versatile bag on this list because it is light and warm while also having the ability to open at the foot or be used like a blanket in warmer weather. This can be nice if you only want to own one bag and know that your trips will take you through mountains and deserts in all seasons.
Tube-style bags, like the Feathered Friends Tanager 20 CFL Sleeping Bag, can be less versatile than hoodless zippered bags or quilts because they have fewer venting options.
Many of the sleeping bags in this guide are made with ultralight shell materials that sometimes appear scarily thin. The 7-denier shell on the Feathered Friends Tanager 20 CFL Sleeping Bag is an example of a shell material that should be treated with care. That said, not all shell materials are created equal, and it’s possible that the 7-denier shell on the Tanager could actually outlast 10-denier or 15-denier materials on some cheaper bags.
One of our testers has been using the Tanager very regularly for over a year and it hasn’t abraded or leaked any down. On several occasions, a dog walked across it leaving no evidence at all of her passing.
A different bag that did not make it into this list wasn’t so lucky, with the dog’s claws going right through the 10-denier material like it was butter. This bag’s main issue was a lack of ripstop within the fabric. Ripstop is a woven fabric with a grid of stronger reinforcement fibers in it to make it more resistant to ripping. Choose a sleeping bag fabric with a ripstop no matter the denier.
Sleeping bag durability refers not just to the shell material but also to 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.
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. In general, a larger coil will last longer than a smaller coil. We’d recommend sleeping bags with #5 coil zippers such as the REI Co-Op Magma 15 Sleeping Bag – Men’s over bags with #3 zippers such as the Enlightened Equipment Convert 20 Quilt Sleeping Bag for this reason.
Every sleeping bag on this list is constructed with ultralight shell and liner materials and high-quality down for excellent packability. The smallest packing sleeping bag on our list is the Feathered Friends Tanager CFL 20 Sleeping Bag with a packed size of 5.5 x 11 inches. 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.
Why You Should Trust Us
The iRunFar team has been fastpacking for over a decade, and we have watched this adventure niche grow. What started off 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 making the next day’s miles possible. We frequently have no idea where we’re going to 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 personal rotation for a few years, this year we set out to research dozens and test 14 of what we thought could be the best sleeping bags for three-season fastpacking and ultralight backpacking.
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. A team of fastpackers with a huge diversity of body types put these ultralight sleeping bags to the test in a range of temperatures and environmental conditions to help you decide what bag will work best for you.
Please note that in the outdoor equipment world product models are routinely discontinued, while new ones frequently come to market. At the same time, we here at iRunFar often keep using our top picks in our daily running… they’re our top picks, after all! Sometimes that continued use results in uncovering product failures. With all this – product discontinuations, product introductions, and product failures – in mind, we routinely update our buyer’s guides based on past and ongoing testing as well as research by our authors and editorial team. While these updates can appear to be us pushing the newest product, it’s anything but that. When we update any buyer’s guide, most of the products are likely to remain the same. That matches our goal: to get you in the best gear that you’ll be using for a long time.
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 a whole lot of nuance. Higher fill-power sleeping bags are lighter, will be warmer for the weight, and will last longer than lower fill-power sleeping bags. The only downside is the cost.
In our opinion, however, this is one area where we’d recommend plunking down 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 use the highest grade down of any on our list.
How should my sleeping bag or quilt fit?
Fit is somewhat subjective, so we won’t give you any absolutes here. But keep in mind when shopping for a fastpacking sleeping bag that narrower bags will generally be more thermally efficient, meaning they’ll be warmer for the weight than wider sleeping bags. Wider sleeping bags create a lot of air space between your body and the bag, which can sometimes be difficult to warm up.
If you know you just can’t stand narrowness and would prefer wider bags for comfort, take a look at quilts because the shoulder girth is adjustable. The shoulder girth of the Katabatic Gear Alsek 22F Quilt can be widened to a measurement of around 66 inches and also narrowed 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 have hydrophobic or water-repellent down. This means that the down clusters themselves have been treated with a durable water-repellent (DWR) chemical coating. Third-party tests show that this treatment does indeed increase the water resistance of the down. What’s less clear is how long this treatment will last or if it affects the long-term lofting ability of down.
Some major brands such as Western Mountaineering and Feathered Friends still haven’t adopted the use of treated down. But if you want a little extra peace of mind during fastpacking adventures in a wet climate, it probably couldn’t hurt to choose a bag with hydrophobic down.
These 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 your fastpack, sleeping pad, tent, and sleeping bag. Excellent budget options are available in every category with the exception of 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 $245!
But because a high-quality sleeping bag can easily last 20 years, we would recommend saving up for a good one. We chose our top pick, the Feathered Friends Flicker UL 20 Quilt Sleeping Bag, with this in mind. At $489, it’s expensive no doubt, but if you take care of it it will continue performing well for you in virtually any fastpacking scenario for at least two decades. Think about it, if a $500 sleeping bag makes it 20 years, that’s only $25 a year.
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 of the bag is smaller than the outside of the bag. This essentially makes it more difficult for a jutting elbow or a knee to compress the insulation, and thus prevents cold spots. Constructing a bag with a differential cut is a little more time-consuming than just sewing two pieces of equally-sized fabric together, so these bags are usually more expensive.
That said, we don’t think it’s mandatory for a sleeping bag to have a differential cut. Lack thereof saves money, making bags like the Outdoor Vitals StormLoft Down TopQuilt 15 available to more people. And in our experience, the bags in 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 an overall longer lifespan. The main benefit of synthetic sleeping bags is that they remain warm even when wet. 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 Feathered Friends Tanager 20 CFL Sleeping Bag 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 also are adjustable in width, widening for comfort and snugging in 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 suffer from drafts. The cordage or webbing used to affix them to your sleeping pad can be a pain to fiddle with, especially when you’re tired and cold.
For those reasons, we recommend sleeping bags for those who don’t want to put all that much thought into setting up their sleep system. You just get in it and pass out. Quilts have a bit of a learning curve.
Do I need a sleeping bag liner?
Sleeping bag liners do three things: They increase the warmth of a sleeping bag, increase comfort for some people, and protect the bag from your skin oils and your filthy fastpacking feet. Some of us at iRunFar like to use them on every trip, primarily for comfort. They will add weight to your kit, though.
Others at iRunFar suggest that you carry baselayers and socks that are dedicated to sleeping. This will reduce redundancy as these items can be used in conjunction with your other layers more effectively than a sleeping bag liner. For example, on the last day of your trip, you can make your feet happy by hiking or running in your sleeping socks.
I sleep cold at night, which sleeping bag should I get?
Instead of looking at temperature ratings, note how much down is in each sleeping bag you’re trying to choose between. For example, the Feathered Friends Swallow UL 20 Sleeping Bag has 16.8 ounces of 950-plus fill down in it and is rated at 20 degrees Fahrenheit. The REI Co-op Magma 15 Sleeping Bag has a lower claimed rating — 15 degrees Fahrenheit — but has less down, a lower grade of down, and a wider cut. In this case, the Swallow will be a far warmer bag than the Magma. Our testing proved this, with all testers agreeing that the Swallow was the warmest bag we tried.
I sleep hot at night; which sleeping bag should I get? Are quilts for hot sleepers?
Most sleeping bags on our list can be ordered in different temperature ratings. Our top pick, the Feathered Friends Flicker UL 20 Quilt Sleeping Bag can also be ordered in 30- or 40-degree 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 20 Quilt Sleeping Bag or the Enlightened Equipment Convert 20 Quilt Sleeping Bag. These bags provide more venting options than any others on our list. You can uncinch the drawstring and poke your feet out or unzip the entire thing and drape it over you like a blanket if you get too hot.
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 20 Quilt Sleeping Bag because it doesn’t unzip all the way or open at the feet.
How should I take care of my sleeping bag? How do I wash my 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 leave your sleeping bag compressed for any longer than you need to. Too much compression can reduce the lofting ability of down.
Store your sleeping bag hanging or in a large, breathable storage bag where it can loft as much as possible. If you plan to hang your sleeping bag, do so in a closet with a door that closes. Cats love to climb sleeping bags as one of our testers has tragically discovered.
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 make sure all the soap is gone. Set the drier to low and tumble it with three tennis balls to break up clumping down clusters.
I ripped a hole in my sleeping bag, what do I do?
We recommend that you carry stick-on patches on your fastpacking trips so that you can field-repair sleeping bag holes. A single sheet of Tear Aid Type A should be plenty. First, cut the patch so that it will cover the tear completely and round the corners so that 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 could last a long time but may not make it through several laundry cycles. If the tear is large, contact the manufacturer to see if they will sew a more permanent patch over the tear before laundering.
Why didn’t you test my favorite fastpacking sleeping bag?
We’d love to test everything out there, and in fact, we have a huge list of sleeping bags we hope to test in the future. If your favorite sleeping bag or quilt didn’t make it in our buyer’s guide, let us know about it in the comments and why you chose it over all the other options on the market!
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?