testing the best backpacking sleeping bags in the woods

Best Backpacking Sleeping Bag Comparison Table

Sleeping Bags Price ($) Weight (oz) Fill Power Fill Weight (oz)
Zpacks Mummy 20 539 23.2 900 15.6
Sea to Summit Spark 18 509 23.5 850 15.2
Therm-a-Rest Hyperion 20 549 20 900 12.5
REI Co-op Magma 15 399 28.2 850 15.9
Sea to Summit Flame 25 509 23.5 850 15.5
Zpacks Zip Around 20 479 21.6 900 14.5
Zpacks Classic 20 449 18.8 900 13.7
MH Bishop Pass 15 285 37.4 650 22.0
Kelty Cosmic 20 165 42 550 16.4

Full Reviews

Best Sleeping Bag for Backpacking

Zpacks Mummy Sleeping Bag 20

The Zpacks 20F Mummy Sleeping Bag is our pick for the singular best sleeping bag for backpacking with the highest performance, traditional-style chassis in terms of warmth-to-weight ratio. This is a true ultralight sleeping bag, and top notch materials keep the weight to only 23.2 oz. Read more in our full-length Zpacks Mummy Sleeping Bag Review.

  • Weight: 23.2
  • Price: $539
  • Down: 900 fill power RDS hydrophobic goose down
  • Fill Weight: 15.6 oz
  • Fabric: 7D Ventum Ripstop Nylon
  • Estimated Comfort: +25 F
  • Pros: Ultralight. High warmth-to-weight. Converts to blanket.
  • Cons: Expensive. Slightly delicate.


It’s constructed with 7D Ventum ripstop nylon which is comfortable, breathable, wind/water resistant.  We find it’s durable enough for most backcountry use. Its baffles are overstuffed (by 30%!) with 900 fill power RDS hydrophobic goose down. Overstuffing reduces cold spots due to down drift, and is a very desired feature that adds minimal weight.

It’s even protected from snagging on its own zipper by the full length zipper guard. But like most ultralight sleeping bags, it’s a bit more delicate than average. Handle with care and it will last many years.

On colder nights, we love cinching down the hood to stay cozy, and on warmer nights, we love how it can fully unzip and convert into a blanket for better ventilation. Or just zip open the footbox to add airflow. It is available in three lengths (short, medium, long) and two widths (standard, broad) to accommodate a wide variety of bodies.

We have zero major knocks against this excellent product and feel it raises the industry-wide bar for backpacking sleeping bag performance.


It’s as simple as this. If you want the best sleeping bag for backpacking that money can buy, choose the Zpacks Mummy 20.

Second Best Sleeping Bag For Backpacking

Sea to Summit Spark Ultralight 18 Sleeping Bag

The Sea to Summit Spark 18 is another top ultralight sleeping bag with a standout warmth-to-weight ratio and very high performance attributes.

  • Weight 23.5 oz
  • Price: $509
  • Down: 850 fill power RDS hydrophobic down
  • Fill Weight: 15.2
  • Fabric: 10d Nylon face, 7D Nylon liner
  • ISO Tested Comfort: +29 F
  • Pros: Ultralight. Good warmth-to-weight. Widely available.
  • Cons: Expensive. Too many horizontal baffles.


The Spark and its sibling the W’s Flame 25 are the most premium models from Sea to Summit, and one of the very best pairs of backpacking sleeping bags from a mainstream outdoor brand. Thanks to their quality and popularity, we find they are the most widely distributed among our top 5 performing bags, and at time of posting, are the best performance ultralight bags sold at REI.

The Spark Ultralight will outperform just about any sleeping bag for backpacking, but still plays second fiddle to the Zpacks ultralight sleeping bag range. This is thanks to the use of great-not-best 850 fill power down, and light-not-lightest 10D Nylon. Upgrading those two elements could save a bit extra weight.

We like the Spark’s baffle design and agree that vertical on the chest and horizonal on the legs is the way to go.  However, the horizontal baffles run too far up the bag, as side sleeper hips will cause plumes to drift sideways and down, potentially creating cold spots.

It also features a full length zipper which does a good job of venting in warmer conditions.


This is a great sleeping bag, and we also like it’s women’s specific variant, the Flame 25. If you’re gearing up and want to save weight, you can’t go wrong with the Sea to Summit Spark 18 Ultralight.

Third Best Sleeping Bag For Backpacking

Therm-a-Rest Hyperion 20

We value warmth-to-weight above all else in an ultralight sleeping bag for backpacking,  which is why we like the Therm-a-rest Hyperion 20. Based on our estimation, it has one of the highest warmth-to-weight ratio of any conventional 20F ultralight sleeping bag from a mainstream outdoor gear brand. It’s only bested by designs from ultralight cottage industry brands like Zpacks.

  • Weight: 20.0 oz
  • Price: $550
  • Down: 900 fill power hydrophobic goose down
  • Fill Weight: 12.5 oz
  • Fabric: 10D Nylon Ripstop
  • ISO tested comfort: +32 F
  • Pros: Ultralight. High warmth-to-weight.
  • Cons: Expensive. Narrow. Slightly under-filled.


This is achieved through the use of 900 fill power down, in conjunction with a relatively lightweight 10D shell fabric, and a snug fit. Additionally Therm-a-rest also states that they have intelligently distributed the down. In this ultralight sleeping bag, 70% of the plumes are in the top section where it works harder to insulate rising heat.

Prioritizing the top insulation and de-prioritizing the back is quilt-like in its design mentality, and we think it’s a cool and innovative choice. We believe that is at least part of what allows Thermarest Hyperion 20F to be lighter than almost all similarly comfort temp rated bags. But it likely requires a high R-Value sleeping pad, like the Therm-a-Rest NeoAir XLite NXT.

As you can see in the photo, Hyperion has a pretty slim design, and an exceptionally small footbox. While decreasing interior volume decreases comfort, it increases warmth. Heat radiating off one’s body is condensed throughout a smaller total space, rather being distributed and diluted.

In this case, our modeling agrees with ISO that this bag is comfortable down to 32 degrees and think it will handle most 3-season backpacking conditions with aplomb. However, if you run cold, you consider a bag with a slightly lower comfort rating.


The Them-a-Rest Hyperion 20F is a narrow mummy, but otherwise an incredible backpacking sleeping bag, and will serve ultralight backpackers very well.

Best Value Backpacking Sleeping Bag

REI Magma 15 Sleeping Bag

If you care about getting the most bang for your buck, then we recommend the REI Co-op Magma 15. This is a very high end backpacking sleeping bag, that hits all the right marks to make it the top dog in the $400-and-under category.

  • Weight: 28.2 oz
  • Price: $399
  • Down: 850 fill power RDS hydrophobic goose down
  • Fill Weight: 15.9
  • Fabric: 15D Pertex ripstop nylon
  • ISO tested comfort: +28 F
  • Pros: Excellent value, great all-around-performance. Draft tube
  • Cons: Not quite ultralight.


It is manufactured with high quality ingredients such as 850 fill power hydrophobic RDS down, and Pertex brand 15D ripstop nylon.

This sleeping bag for backpacking lands at the intersection of lightweight and ultralight. At 28 oz it’s slightly heavier than the best of the best ultralight sleeping bag, but still lighter than virtually all other backpacking sleeping bags, and especially those costing under $400. Cozy up with the neck draft tube and enjoy a premium warmth-to-weight ratio at a less than premium price.

We slightly ding REI Co-op’s use of horizontal baffles over the chest, which can cause down to drift down and to the sides leaving a coldspot above the torso. But we commend them on their excellent warranty and customer service, so it’s a give and take. This sleeping bag also comes in a women’s version with more room in the hips and less at the shoulders.


All in all, the REI Co-op Magma 15 is a great all-around backpacking sleeping bag, and only surpassed in performance by more expensive best-in-class alternatives.

Best Women’s Specific Backpacking Sleeping Bag

Sea to Summit Flame Ultralight 25 Sleeping Bag

The Sea to Summit Flame 25 Ultralight Sleeping Bag is designed specifically for women, and to address the fact that, physiologically speaking, women sleep a bit colder than men. They accomplish this by narrowing the shoulders and widening the hips for a better fit and filling the sleeping bag with extra of 850 fill power RDS hydrophobic down.

  • Weight 23.5 oz
  • Price $509
  • Down: 850 fill power dry down
  • Fill Weight: 15.5
  • Fabric: 10D Nylon
  • ISO tested comfort: +25 F
  • Pros: Incredible warmth-to-weight. Designed for women. Widely available.
  • Cons: Confusingly honest temp rating. Too many horizontal baffles.


Unlike most other backpacking sleeping bags, the temperature number referenced in “Flame 25” is not the lower sleep limit, but rather, it’s comfort rating. For context, it has about half an ounce more down fill than its sibling, the Men’s Sea to Summit Spark 18. Mind you, the 18 in Spark 18 refers to its lower sleep limit, not its comfort rating.

The Flame 25 (which, given the above, could have been called Flame 18) is a great all around 3-season sleeping bag for backpacking that hits all of the right notes and weighs in at an ultralight 23.5 oz.

It is constructed with ultralight 10D nylon exterior and 7d liner, only marginally inferior to our preferred build of entirely 7D for max weight savings. Good quality 850 dry down insulates while minimizing bulk and weight. That said, 850 is no longer top tier. The Flame 25 has a mostly full-length zipper that runs all the way to the ankles.

We love the use of split vertical-horizontal baffling. This prevents cold spots from forming as plumes won’t drift down and away from center on the vertical baffles. However, they should have carried the vertical baffles lower down the bag in place of the 2-3 of the horizontal baffles at the hips. Side sleepers will make a high point with their hips that could form cold spots.


The Flame 25 hits all of the right notes for a backpacking sleeping bag and is nearly identical to the comparable Sea to Summit Spark 18. While the naming convention is slightly confusing, trust us that this is a great bag, and comparable warm to most others with a 15-20 in their name.

Best Hoodless Ultralight Sleeping Bag For Backpacking

Zpacks Zip Around Sleeping Bag 20

If you’re willing to omit the hood, Zpacks Zip Around 20 will deliver the best backcountry performance in an ultralight sleeping bag. Without a hood, it is able to achieve the low low weight of only 21.6 oz, thus offering one of the highest warmth-to-weight ratios on the market. Read more in our full-length Zpacks Zip Around 20 Review.

  • Weight: 21.6
  • Price: $479
  • Down: 900 fill power RDS hydrophobic goose down
  • Fill Weight: 14.5
  • Fabric: 7D Ventum ripstop nylon
  • Estimated comfort: +25F
  • Pros: Ultralight. High warmth-to-weight. Converts to blanket. Versatile.
  • Cons: Slightly delicate. Hoodless.


But what makes this one so special is the full length 2-way, namesake “Zip Around” zipper venting feature. When it gets cold, zip up and cinch down the top for maximum warmth retention. But on warmer nights, you can also vent the footbox or fully unzip to convert the sleeping bag into a flat blanket.

Also great for use around camp! It’s like buying a 2-for-1, 20 and 40 degree sleeping bag. It’s just so practical for the wide array of temps a backpacker will face in one season.

This sleeping bag for backpacking is constructed with 7D Ventum ripstop nylon which is comfortable, breathable, wind/water resistant, and we find it’s durable enough for most backcountry use.

Its baffles are overstuffed (by 30%!) with 900 fill power RDS hydrophobic goose down. Overstuffing reduces cold spots due to down drift, and is a very desired feature that adds minimal weight.

It’s even protected from snagging on its own zipper by the full length zipper guard. But like most ultralight sleeping bags, it’s a bit more delicate than average. Handle with care and it will last many years.

If you’re unsure about going hoodless, consider this: You can always wear your hat, your mid-layer hood, and/or your puffy hood to bed, or buy a modular down hood to supplement. We’ve ditched sleeping bag hoods and haven’t looked back. Our head always stays plenty warm enough.


As far as ultralight sleeping bags go, we feel that Zpacks singularly dominates the marketplace with three of the best options. Sure, it ain’t cheap, but the Zpacks Zip Around still outperforms sleeping bags from other brands that cost $100 more. This is a seriously excellent ultralight sleeping bag and we recommend it highly.

Highest Warmth-to-Weight Hoodless Ultralight Sleeping Bag

Zpacks Classic Sleeping Bag 20

For those who feel untethered by hoods, Zpacks Classic Sleeping Bag offers the single highest warmth-to-weight ratio among all zippered sleeping bag.

  • Weight: 18.8 oz
  • Price: $449
  • Down: 900 fill power RDS hydrophobic goose down
  • Fill Weight: 13.7 oz
  • Fabric: 7D Ventum ripstop nylon
  • Estimated Comfort: +25F
  • Pros: Ultralight. Best warmth-to-weight. Great value.
  • Cons: Hoodless. Slightly delicate.


The design is a best-of-both-worlds hybrid quilt-sleeping-bag. It has the weight of a quilt and can be used unzippered, just like a quilt. But when it gets cold, you can zip it up into a 100% draft-free sleeping bag mode and cinch down the neck to prevent any heat from escaping.

It’s constructed with 7D Ventum ripstop nylon which is comfortable, breathable, wind/water resistant, and we find it’s durable enough for most backcountry use. Its baffles are overstuffed (by 30%!) with 900 fill power RDS hydrophobic goose down. Overstuffing reduces cold spots due to down drift, and is a very desired feature that adds minimal weight.

But like most ultralight sleeping bags for backpacking, it’s a bit more delicate than average. Handle respectfully and it will last many years. The zipper runs along the bottom of the bag and isn’t very noticeable when slept on, but if it bothers you, you can always rotate the bag slightly to alleviate pressure points. This sleeping bag is so warm (relative to its weight) that you will probably use it unzipped more often than zipped.


We love the Zpacks Classic for its incredible low weight and incredibly high, best-in-class warmth-to-weight ratio. This ultralight sleeping bag is the closest you will get to a true quilt without sacrificing the zipper-enclosure.

Best Sleeping Bag For Backpacking Under $300

Mountain Hardwear Bishop Pass 15 Sleeping Bag

The Mountain Hardwear Bishop Pass 15 is our favorite mid-tier backpacking sleeping bags, and a great pick up for under $300. This one will reliable keep campers warm, even when temps drop below freezing, and with 30 denier nylon, it’s basically indestructible. That makes it an excellent backpacking sleeping bag for hikers with dogs or kids.

  • Weight: 37 oz
  • Price: $285
  • Down: 650 fill power RDS down (80% down plumes, 20% feathers)
  • Fill Weight: 22.0 oz
  • Fabric: 30D nylon
  • ISO tested comfort: +26 F
  • Pros: Fully-featured. Affordable. Good value. Durable.
  • Cons: Midweight


All of that durability and cost savings add weight. and at 37 oz, This sleeping bag for backpacking isn’t pushing any performance boundaries. It is definitely not an ultralight sleeping, and just barely sneaks into the the midweight category. 650 fill power down (mixed with feathers) is another cost savings choice at the expense of adding weight.

One nice thing is that the Bishop Pass is a backpacking sleeping bag with all of the bells and wells. Mountain Hardwear gives us a draft collar, and internal stash pocket,  a full lenght 2-way zipper with anti snag guards, and glow-in-the-dark zipper pulls. It’s a classic mummy shape to conserve heat, and the women’s version is narrowed at the shoulders and widened at the hips which we love.

It comes with a stuff sack and a home-storage bag. We haven’t tried this, but the listing claims it can be zipped to another compatible Mountain Hardwear sleeping bag with a right zipper to create a bed for two. That’s pretty neat!

Mountain Hardwear uses 650 fill-power down and a 20D nylon shell, which are not the lightest weight materials but it helps cut costs and also makes the bag very resistant to tears and snags.

With a +26 comfort limit, this bag will perform in most three-season conditions or even a bit colder, especially with a warm sleeping pad and clothing. There’s a full length draft tube down the zipper to prevent heat loss in this area, as well as an internal stash pocket (a feature we don’t see often but love!).


This is a pretty solid sleeping bag for a solid price. Our biggest complaint is that it’s just kind of heavy and bulk.

Best Sleeping Bag For Backpacking Under $200

Kelty Cosmic 20 Sleeping Bag

If you have no more than $200 to spend on a backpacking sleeping bag, grab the Kelty Cosmic 20. Everything about it is basic, but it will keep you comfortably warm down to freezing. And it does so without entirely taking over your backpack or breaking the bank.

  • Weight: 42 oz
  • Price: $165
  • Down: 550 fill power hydrophobic duck down
  • Fill Weight: 16.4
  • Fabric: 20D nylon outer, 50D polyester inner
  • ISO tested comfort: 32
  • Pros: Very affordable. Good value. Durable. Lots of features.
  • Cons: Heavy. Bulky.


First of all, the price! Just $165 in a men’s size regular is about all you can ask.

The Kelty Cosmic 20 Sleeping Bag for backpacking saves the buyer money by utilizing 550 fill power down. We’re glad they’ve treated it to be hydrophobic. And while it’s objectively low grade, you still get the long-lasting, lightweight compressibility benefits of down plumage.

At 42 oz, it ain’t no ultralight sleeping bag, and it costs about 1/3 as much so no complaints. As far as features go, you get double separating zippers and a snag guard, as well as an internal stash pocket and a draft tube. Not bad!

Kelty notes that the Cosmic’s baffles are designed in a trapezoidal configuration which increases thermal efficiency. We’re not sure exactly how or why, but maybe there’s something to it.

The biggest travesty with this recommendation, however, is that the women’s model costs $50 more. That’s because women sleep colder, so to earn the same 20 degree rating/32 degree comfort rating, it requires significantly more down insulation which adds cost. It’s also widened at the hips and narrowed at the shoulders for a better fit.


All said and done, this is a popular, easily found sleeping bag for $200 or less that keep campers warm down to freezing. It’s the best budget down bag we know of.

Best Backpacking Sleeping Bag Accessories

Best Backpacking Sleeping Pad

Therm-a-Rest NeoAir XLite NXT Sleeping Pad

New for 2023, the Therm-a-rest NeoAir XLite NXT (shop now) is currently the undisputed best performance sleeping pad for backpacking that money can buy, and it has no equal. It is statistically superior in almost every way and across all measurements when compared to all other sleeping pads. Read more in our full-length Therm-a-Rest NeoAir XLite NXT Review.

  • Price: $210
  • Weight: 13 oz
  • R-Value: 4.5 | R-Value/Weight: .35
  • Thickness: 3”
  • Fabric: 30d
  • Sizes: Regular Short, Regular, Regular Wide, Large
  • Pros: Comfy. Thick. Ultralight. Very High R-Value-to-weight.
  • Cons: Expensive.


NXT’s R-Value of 4.5 is one of the highest among three season pads, and with a weight of only 13.0 oz, it’s also one of the very lightest. It’s so far ahead of the pack, that compared to the second best sleeping pad, its R-value-to-weight ratio is 24% higher.

XLite NXT is no slouch on comfort either. Now with an additional half inch of thickness compared to the original, XLite NXT is 3” thick, which means you can basically ignore small roots and divots in the ground, and side and back sleepers will be happier. And what’s more, compared to previous editions, it’s designed to be much quieter.

While it’s definitely still a bit crinkly, we’d describe the overall volume as average and acceptable. At time of publishing, Therm-a-Rest states it is six times quieter than the original XLite on their homepage. While it did get noticeably quieter, our experience did not indicate 6X.

Inflation with NXT can be a bit of a chore considering how thick the pad is. But the “winglock” valve is excellent, and you don’t have to constantly tighten it in between breaths or pumps. The 30D fabric is very durable, and you shouldn’t have any problems so long as you aren’t using it on scratchy surfaces.


This is the best overall sleeping pad for backpacking that has ever been manufactured, and we can’t wait for you to try it out! Enjoy!

Best Backpacking Pillow

Hyperlite Mountain Gear Stuff Sack Pillow

We love the 9L Hyperlite Mountain Gear Stuff Sack Pillow for dry gear storage and improving quality of sleep.

  • Weight 1.7 oz
  • Price: $59
  • Size: 12×17″
  • Fabric: DCF 8, 100 weight-fleece lining
  • Pros: Comfy. Doubles as dry bag stuff sack. Ultralight.
  • Cons: Doesn’t work if you’re wearing all of your layers to bed.

Features and Verdict

A great 2-for-1. Constructed with waterproof durable Dyneema, zipper access, and a reversible fleece interior lining for pillow-mode. It gives a lot of utility for 1.7 ounces.

The large size fits a puffy jacket and/or some extra layers. We find it is comfier than inflatable pillows. Grab one of these, you will not regret it!

Best Ultralight Dry Bag

Hyperlite Mountain Gear Roll Top Stuff Sack

Hyperlite Mountain Gear Roll Top Stuff Sack is a classic dry bag made out of Dyneema. The DCF11 fabric is extremely durable, lightweight, long lasting, completely waterproof, and just feels indestructible and high quality.

  • Weight: 2.0 oz
  • Price: $79
  • Materials: DCF11
  • Volume: 43 L
  • Pros: Ultralight. Ultra durable. Best-in-class. Voluminous.
  • Cons: Expensive.


The 25L size L is probably the most universal, but we love the 43L XL, which is . 4oz heavier and big enough to store a 4-season sleeping bag, puffy, and all extra clothes without over compressing.

If you’re going to spend that much on one dry bag, you might as well get the one size that fit’s all. And it’s compatible with winter camping bulk.


This is an excellent ultralight dry bag fit for an ultralight backpack. For less expensive (but less durable) ultralight dry bags, turn to the Sea to Summit Ultra-Sil Dry Bags.

Best Down Wash

Nikwax Down Wash Direct

When you notice your down sleeping bag or jacket starting to look a bit less puffy than it used to be, it’s time to use Nikwax Down Wash Direct. By cleaning the plumes, you reinvigorate the down’s loftiness, re-puff the baffles, and ultimately increase the warmth retention of the garment.

  • Weight: 0 oz | Price: $13
  • Technology: Down-safe soap.
  • Pros: Renews loft. Cleans. Safe. Biodegradable.
  • Cons: Never quite restores 100% of original loft.

Features and Verdict

We tend not to get our down pieces very dirty in the first place, but still like to wash them about once per year of heavy use, or every other year with moderate to light use. Down washing is an important and underrated aspect of gear maintenance and most people do it too infrequently.

Nikwax recommends using this detergent in the tub for large garments like sleeping bags, or a large professional-grade front loading washing machine. Dry it out afterwards by tubmle drying on low heat settings. It even works on DWR-treated hydrophobic down. The only bummer is that even a thorough washing and drying will only restore the down to about 90% of its original puffiness.

The wear and tear caused by bodyweight and compression storage will slowly degrades the plumes, and you will never quite get a full factory reset.

But that’s not Nikwax’s fault, and we highly recommend Nikwax Down Wash Direct to get the most out of your down products.


Best Repair Patch

Gear Aid Tenacious Tape Repair Patch

For small to mediums sized rips and tears, we prefer using a Gear Aid Tenacious Tape Repair Patch, precut in a hexagonal shape.

  • Weight: 0.1 oz (once applied)
  • Price: $5
  • Technology: Tenacious Tape
  • Cons: Long lasting. Works in backcountry. Very adhesive. Waterproof.
  • Cons: Requires smooth surfaces


When applied to a smooth, relatively clean surface, the repair patches are incredibly long lasting and durable. The adhesive is significantly stickier than duct tape. The patch itself is waterproof and will prevent leaks. We recommend the hex shaped patches because the corners are less sharp than rectangles, thus less prone to catching and peeling.

These repair patches work on tents, backpacks, rain jackets, hiking clothes, and pretty much any other fabric item that can be laid flat and smoothed out. However, they won’t work well on textured surfaces, like shoes or mesh.


Nonetheless, Gear Aid makes a best in class product that should be a staple in every hikers repair kit, especially those who use ultralight tents with thin fabric. We always carry them and you should too.


Video Overview of the Best Ultralight Sleeping Bags

Ultralight Sleeping Bag Buyer Information

What makes it an ultralight sleeping bag

For the sake of this guide, we consider any sleeping bag for backpacking that is comfort-rated down to freezing and weighs less than 24 oz in standard/medium/regular sizing to be an ultralight sleeping bag. However, there is no technical definition, and weight benchmarking is also relative to the temperature rating that you are shopping.

For 30 degree bags, we might consider the cut off to be 20 oz since they require less materials. And for 10 degree bags, closer to 30 oz, since they require more down, more fabric to contain the down, and extra interior space to layer.

Why focus on 20 degree sleeping bags for backpacking

For ease of comparison, this buyer’s guide focuses exclusively on 3-season sleeping bags for backpacking with 15-20 degree ratings in their product name. This translates to a 25-30 degree lower comfort limit, which we feel is the most useful, all-purpose insulation level which provides a few degrees of buffer below the lowest temperatures most backpackers will experience in a season.

However just about any sleeping bag for backpacking can also be purchased in 0, 10, and 30 degree versions, and the same recommendation qualifiers apply when comparing models. Unsurprisingly, the best overall 20 degree backpacking sleeping bag is also the best overall 30 degree backpacking sleeping bag.

Warmth-to-weight ratio is key for ultralight sleeping bags

Sleeping bags for backpacking have one main job – keep us warm. And so long as they’re doing that, the next most important thing is not to weigh down the backpack when carried.

That’s why our guide focuses on warmth-to-weight ratio as the ultimate measure of performance for backpacking sleeping bags. We’ll pass on all of the bells and whistles, so long as you give us a high warmth-to-weight sleeping bag at a good price.

Most features are nice, but not necessary

While significantly less important than having a good warmth-to-weight ratio, other features are worth considering to evaluate the entire user experience. Zipper snag guards, and the ability to cinch down around your head or neck are the two most important. But beyond that, which are worth their weight is fairly subjective.

Convertible blankets are very nice, especially in summer. We usually prefer a sleeping bag for backpacking wit  a sewn footbox to ventilated ones for maximizing warmth-to-weight. But an exception would be made for 30 degree summer backpacking sleeping bags. Internal pockets are generally unnecessary, and we rarely go for draft collars except when winter camping.

a woman uses a therm-a-rest sleeping bag or quilt in the desert

Zpacks raises the bar for ultralight sleeping bags

And speaking of the very best, you will notice that three of our favorite ultralight sleeping bags, including our top pick, are manufactured by one brand – Zpacks. Applying strict ultralight design methodology, Zpacks has created a range of sleeping bags for backpacking with objectively higher warmth-to-weight ratios than their competitors and completely raised the bar when it comes to performance and versatility.

To rate any other ultralight sleeping bag above theirs would be dishonest gear reviewing, and we sing their praises loudly and proudly. Go Zpacks!

Down and fill power

High quality down plumes are the most important part of a backpacking sleeping bag’s ability to loft and insulate. Down plumes are rated according to the amount of square inch volume taken up by one ounce. 900+ fill power is considered the loftiest, highest quality, most expensive down.

A sleeping bag for backpacking with fill power ranging from 850-950 is considered good. Fill powers from 750-850 are mid-tier. 550-750 is now considered low grade.

We’ve even noticed 1,000 fill power down being used recently, and while this is a strict performance upgrade, we’re worried that the most voluminous plumes would also be most susceptible to damage with use over time, and quickly degrade to a 900 fill power level, thus making paying extra for it a poor long term investment.

Will higher fill powers continue to be offered as we get better at sifting the best plumes to the top? We will report back as we learn more.

Down vs synthetic insulation for backpacking sleeping bags

As of 2023, high fill power down (900+) still outperforms synthetic insulation in warmth-to-weight, which is why all of the best performing ultralight sleeping bags are still filled with plumes. But technology creeps forward, and every year brings us closer to the day when synthetics surpass down in terms of performance.

At time of posting, top tier synthetic insulation appears to be edging out low-to-mid-tier down fill power, and is creeping towards equalling 800 fill power. And when manufactured with recycled materials, synthetics are beginning to appear as the more ethical choice too. We’re keeping our eye on the development of synthetic insulation for backpacking sleeping bags, and will report back as developments occur in this niche.

Fabrics and ultralight sleeping bags for backpacking

The best ultralight sleeping bag fabrics are the lightest ones that reliably encase down, and are just durable enough for backcountry use. To maximize warmth-to-weight, it is important to minimize fabric, as it is a low contributor of insulation. Ripstop nylon still reigns supreme here, and we prefer it in 7 denier (7D). If you’re hard on gear, we recommend you find a sleeping bag for backpacking with a 10D+ Ripstop nylon.

Backpacking Sleeping Bag Baffles

From a performance perspective, it is preferable to sew vertical baffles (paralleling the body) along the chest and legs of a sleeping bag. This is compared to horizontal baffles (running perpendicular to the body) in which gravity will slowly cause down plumes to drift off the top center of the body and down to the lower sides. This exposes a cold spot directly on top of the sleeper and must be prevented. This is a particularly egregious problem for side sleepers, who should make sure their sleeping bag for backpacking has vertical baffles from the hips up.

Ultralight Quilt > Ultralight Sleeping Bag

It is our long-held belief that the best ultralight quilt will easily outperform the best ultralight sleeping bag for backpacking in terms of warmth-to-weight, value, and overall user experience. Quilts are composed only of the three hardest working parts of a sleeping bag (top, sides, footbox) and cut the three least hard working parts (zipper, hood, back).

Compared to down and nylon, zippers are relatively heavy and provide no insulation. Compared to fully lofted down on the top and sides of a sleeping bag, down that is compressed underneath the weight of your body and hood is relatively ineffective. By doing away with zippers, backs, and hoods, camp quilts reduce production cost, save weight, shave the least effective components, and increase warmth-to-weight ratio.

When not testing a sleeping bag for backpacking, we always choose a quilt. But we understand why people love sleeping bags. The sensation of fully zipping up and tucking into the hood is cozy and hits just right. That’s why we fully endorse the ultralight sleeping bags in this guide. But if you want to crank up performance even higher, check out our buyer’s guide for the best ultralight quilts.

Hoodless Backpacking Sleeping Bags > Hooded

Similar to quilts but not quite as minimalist, we also like a hoodless ultralight sleeping bag chassis over traditional models. Along with the zipper and back, the hood is one of the three least hard working parts of a backpacking sleeping bag, and by removing it, the warmth-to-weight ratio is improved.

Maintaining an Ultralight Sleeping Bag For Backpacking

While unpacking from your trip, make sure to dry out and re-fluff your backpacking sleeping bag. We recommend running it through a front loading dryer on low for 10 minutes, or until dry. Store it in the big cotton bag it came with rather than compressed in a dry bag. If you notice that your sleeping bag is slowly losing loft, try washing it with Nikwax downwash.

With use over time dirt and body oils will slowly start to penetrate the fabric and build up on the plumes. This degrades their loftiness, thus decreasing the insulating ability of your sleeping bag. We find that washing resuscitates down up to 90% of its original off-the-shelf performance, and we try to do it about once every other year for high-use backpacking sleeping bags.

a woman gazes onto a glacier while testing the best backpacking quilts and sleeping bags

Conclusion Ultralight Sleeping Bags For Backpacking 

The best sleeping bag for backpacking is such because it has a high warmth to ratio, and a low total weight. The ultralight sleeping bags in this buyer’s guide have the highest warmth-to-weight ratios according to our predictive model. Ultralight sleeping bags from Zpacks are a notch above the rest in this way, and they manufacture all three of the best performing sleeping bags available.

But great bags are produced by a variety of brands, and at a variety of price points, and any one on this list would make for your next great backpacking sleeping bag.

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