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Hands-on Gear Review

Kelty Cosmic Down 20 Review

Backpacking Sleeping Bag

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Best Buy Award
Price:   Varies from $120 - $160 online  —  Compare at 3 sellers
Pros:  Affordable, great value bag, hard to find a less expensive 600+ fill down bag, lighter and more compact than most bags in its price range
Cons:  Heaviest traditionally designed down bag we tested, not as warm as other 20 degree bags, roomy cut is amost too roomy
Editors' Rating:     
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Manufacturer:   Kelty


The Kelty Cosmic Down is our top choice for budget backpacking and camping. Whether you're new to the outdoors or you're just due for a new bag that doesn't break the bank, then Cosmic Down 20 is the best option for the money to get you going. There are other bags in our review which are lighter, warmer, and more compressible, but the Cosmic Down offers decent quality for an incredibly good price. It is available in other temperature ratings too, just in case 20 F doesn't fit your needs. See how this sleeping bag compares to others in our Backpacking Sleeping Bag Review.

RELATED: Our complete review of backpacking sleeping bags

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Analysis and Hands-on Test Findings

Review by:
Ian Nicholson
Review Editor

Last Updated:
November 24, 2016

Hands-On Review

The Cosmic Down 20 is not a top-of-the-line backpacking sleeping bag; however it is an affordable bag that gets the job done. We're continually impressed with the versatility and quality of this bag, especially considering its $160 price point.

Performance Comparison

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The Kelty Cosmic Down isn't the nicest bag out there but you'd have a harder time finding a better preforming down bag for its $150 price. Even then it offers respectable weight and packed size for the budget conscious backpacker.


The Cosmic Down 20 is not as warm as other 20F bags in our Best Backpacking Sleeping Bag Review. It features 21 ounces of down insulation, but due to its fairly roomy cut and lower quality 600 fill down, most people will find this bag a lot more comfortable when used closer to 25-30F, rather than 20F. The Cosmic Down features a passive (AKA non-cinching) draft collar that certainly offers more warmth; if it didn't offer this feature, we'd expect that this bag would be even less warm. We think as a whole, adjustable draft collars are warmer most of the time, but may not be as comfortable as the one featured on the Cosmic Down.

While the Cosmic down's large hood could be of higher quality, it does a respectable job of keeping the heat in, especially when compared to other models. We think this bag is warmer than the Kelty Tuck 20 and comparable to the The North Face Cats Meow. It's not quite as warms as the 25F REI Igneo or even close to as warm as the 20F Western Mountaineering UltraLite. All that said, we think that most folks will be toasty enough for a majority of summer time camping and backpacking trips. If temps drop below 30F, backpackers will simply need to layer up.

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The Kelty Cosmic Down is warm enough for most 3-season backpacking trips, but our testers think its more comparable in warmth to most 25°-30° F bags rather than most 20° F options.


A regular sized bag weighs 2 lbs 13 ozs. It's heavier than most down bags and similar in weight to several performance-oriented synthetic models, like The North Face Cats Meow (2 lbs 13 oz) and the 20 F Mountain Hardwear Hyperlamina Flame 20 (2 lbs 13 oz). The Cosmic is over a pound heavier than the 35F Mountain Hardwear HyperLamina Spark 35 (1 lbs 13 oz) and even more so than some of the light weight options made by Western Mountaineering.

While we would not consider it a lightweight option, especially when compared to more expensive down bags in our review, the Cosmic Down is lighter than many bags that are available for the same price, regardless of insulation type. This contender uses 600-fill down, lower quality fabrics, and has a fairly roomy cut; all of these factors contribute to it's heavy weight. While it's slightly on the heavier side, this bag is hardly what we would refer to as oppressively heavy, especially for shorter than average distance backpacking and car camping trips.

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The spacious cut Kelty Cosmic Down (right) offers above average leg room and is an excellent option for tummy and side-sleepers of for folks who just want a little more room. Shown compared to the Western Mountaineering MegaLite (left) and Western Mountaineering UltraLite (center).


This bag offers slightly wider than normal dimensions, providing a spacious interior in which to sleep. Stomach and side sleepers loved this bag because they could bring their knee higher than they could in most bags, increasing the comfort while resting in those positions. The spacious design is certainly bigger than average among backpacking oriented mummy-style bags; for folks who feel like they don't like most mummy bags, this might be an appropriate option to consider.

Despite its fairly large dimensions, our stomach sleeping testers still preferred the Nemo Salsa 30 for its spoon shaped design and stretchy seams. While the fabric on the Cosmic feels okay, it's slightly above average for "feel" among other bags in our review. It's also much more comfortable to sleep in a down bag versus a synthetic bag, if given the option; we enjoyed sleeping in the Cosmic from a coziness standpoint more than any of the synthetic bags we tested.

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The Kelty Cosmic Down shown here packed into its included stuff sack with a one litter Nalgene bottle for size reference. The Cosmic down can pack about 25% smaller in with an after-market compression sack.

Packed Size

The 600-fill down and the lower quality fabrics do not compress as well as bags with higher fill power down and lighter weight fabrics. That said, the Cosmic packs down reasonably well for the price. Overall, there are few, if any, bags that offer similar warmth in addition to the level of compressibility and a $160 price tag. If you're searching for a bag that will offer better packability, we would suggest the Western Mountaineering Ultralite, Western Mountaineering Megalite, Marmot Hydrogen, or Sea to Summit Spark III. Ranging in price from $330-500, these four contenders scored a 10 out of 10 for packed size.

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The Kelty Cosmic Down (far right), while not ultra-small, offers pretty respectable packed size among comparably rated bags we tested and to other options on the market. Its wort noting that for the cost it's very hard to find a comparably warm down bag that compresses as small as the Cosmic Down.


For an entry level sleeping bag, we were happy to see a down insulated option like the Cosmic Down 20. Down allows this bag to be lighter, have a greater level of packability, and offer more comfort than most synthetic sleeping bags. Most importantly, down is more long-lasting; even though the fill-power isn't super high in this bag, the insulation will maintain its loft and insulation 2-3 times longer than that of a high-quality synthetic bag. The Cosmic down features differential pull cords on the collar that are easy to use. We're not convinced that there is a huge benefit to this, but it is nice that Kelty uses water-resistant DriDown, which we feel adds value to this bag and allows it to dry marginally quicker. For a bag that offers more features, consider the Sea to Summit III or the Nemo Salsa 30. Both offer various features, which earned them a 10 out of 10 in the features metric.


The Cosmic Down will work well for car camping and moderate length backpacking trips, but it lacks the warmth, weight, and level of packability for us to consider it a well-rounded 3 season sleeping bag. It is roomy enough to add several layers once the temperature dipped between 30-40F; conversely, its full-length zipper allows for the bag to be completely unzipped and used like a blanket for warm summer nights.

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The Kelty Cosmic down is a reasonable versatile bag. Its warm enough for most 3-season excursions, comfortable enough for car camping, and light and compact enough for shorter range backpacking trips. Its not a super warm 20° F nor is it as compressable, nor as lightweight as we'd like for long range trips. All that said if your on a budget the Kelty Cosmic down will work for most trips and is the best bag you can get your hands on for the price.

The Western Mountaineering bags, along with the Nemo Salsa and The North Face Cats Meow offer a higher level of versatility. The Salsa offers great ventilation and plenty of room, while the Cat's Meow excels on all sorts of trips.

Best Application

The Kelty Cosmic Down is best suited for car camping or backpacking trips where its weight and packed size wont be a big deal. It is a good introductory down sleeping bag for novice or budget backpackers and is warm enough for summer use at low to mid-elevations.

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At $150 the Kelty Cosmic Down is pretty unbeatable. For new hikers or folks on a tight budget we don't think anything comes close to the Cosmic down for $150.


This contender wins our Best Buy Award for its exceptional value. We love the low price, the use of down insulation, and the overall simple design of the bag. At $160, you'd have a difficult time finding a better down sleeping bag that compares in warmth, weight, and packability. For the price, the down insulation will maintain its warmth over time at least twice as long when compared with synthetic models.

Bottom Line

Winner of the Best Buy award yet again, we feel that it is a good entry-level, budget-conscious backpacking sleeping bag. It sacrifices some weight and packability by using lower quality materials in order to meet its low price-point, however its not way lower in performance when compared to other bags of similar quality and price. This bag is still a good choice for summertime use at low to mid-elevations, whether its in your pack, or at the campground.

Other Versions and Accessories

Also available from Kelty is the Cosmic Down 0 and the Cosmic Down 40 versions in regular and long sizes. It is also make in a women's specific model. Check out our Women's Sleeping Bag Review to see how the women's specific model compared to other down sleeping bags in that review.

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Kelty Cosmic Down 0
  • Weight - 3 lbs 9 oz (1 lb more than the 20)
  • Cost - $290.00 ($100 more than the 20)
  • Shape- Mummy
  • Length- 6ft (long size available- 6' 6")
  • Material- 550-fill hydrophobic DriDown
  • Temperature rating- rated down to zero degrees (20 degrees warmer than the 20)

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Kelty Cosmic Down 40
  • Weight - 1 lb 12 oz (13 oz less than the 20)
  • Cost - $140.00 ($50 less than the 20)
  • Shape- Mummy
  • Length- 6ft (long size available- 6' 6")
  • Material- 550-fill hydrophobic DriDown
  • Temperature rating- rated down to 40 degrees (20 degrees cooler than the 20)
  • No top draft collar, like the 20 degree

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Kelty Cosmic Down 20 - Women's
  • Women's version
  • Weight - 2 lb 8 oz (1 oz less than the men's)
  • Cost - $200.00 ($20 more than the men's)
  • Shape- Mummy
  • Length-5ft 8in (4 inches short than the men's)
  • Material- 550-fill hydrophobic DriDown
  • Temperature rating- rated down to 20 degrees
Ian Nicholson

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OutdoorGearLab Member Reviews

Most recent review: November 24, 2016
Summary of All Ratings

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Helpful Buying Tips
How to Choose the Best Backpacking Sleeping Bag - Click for details
 How to Choose the Best Backpacking Sleeping Bag

by Ian Nicholson, Mike Phillips, Max Neale