Kelty Cosmic Down 20 Sleeping Bag Review

The Kelty Cosmic Down 20 Sleeping Bag is one of Amazon’s best-selling outdoor products, but is this sleeping bag actually worth the hype? Our team is putting the Kelty Cosmic to the test, reviewing its features and functionality, and rating whether it’s worthy of your time, money, and attention. Spoiler alert: it most definitely is. 

In this review, we’ll take a closer look at the Kelty Cosmic 20-Degree Sleeping Bag: the most popular model from the Kelty Cosmic line-up. We’ll explore its temperature rating, comfort rating, material, sizing, hardware, and zippers, baffle construction, packability, durability, and other design elements like the draft tube/draft collar and included compression sack. 

However, we’re also reviewing two alternatives: the Kelty Cosmic 0-Degree Sleeping Bag and the Kelty Cosmic 40-Degree Sleeping Bag. One is more suited for cold weather camping and year-round usage, the other more to summertime camping trips. The Kelty Cosmic 20-Degree Sleeping Bag is the most versatile due to its mid-range temperature rating, but perhaps one of the two other models is more suited to your camping needs. 

Our Expert Picks ‘Best Kelty Cosmic Sleeping Bags’ are:

Preview
Kelty Cosmic 20 Degree Down Sleeping Bag - Regular - Ultralight Backpacking Camping Sleeping Bag with Stuff Sack
Kelty Cosmic 550 Dridown Sleeping Bag, Long/4-Degree
Kelty Cosmic 40 Degree Down Sleeping Bag - Backpacking Camping Ultralight Compressible Sleeping Bag - Stuff Sack Included
Title
Kelty Cosmic 20-Degree Sleeping Bag
Kelty Cosmic 0-Degree Sleeping Bag
Kelty Cosmic 40-Degree Sleeping Bag
Type of fill
600-Fill Power Hydrophobic DriDown™
600-Fill Power Hydrophobic DriDown™
600-Fill Power Hydrophobic DriDown™
Lower limit
20°F
0°F
40°F
Outer Shell Material
20D Nylon Taffeta Shell With PFC-Free DWR
20D Nylon Taffeta Shell With PFC-Free DWR
20D Nylon Taffeta Shell With PFC-Free DWR
Liner Material
50D Polyester Taffeta Liner
50D Polyester Taffeta Liner
50D Polyester Taffeta Liner
Weight
2 lb 6.6 oz
3 lb 12.8 oz
1 lb. 12 oz
Packing Dimensions
8 x 15.5 in
10 x 21.5 in
7 x 12 in
Stuff Sack Included
Preview
Kelty Cosmic 20 Degree Down Sleeping Bag - Regular - Ultralight Backpacking Camping Sleeping Bag with Stuff Sack
Title
Kelty Cosmic 20-Degree Sleeping Bag
Type of fill
600-Fill Power Hydrophobic DriDown™
Lower limit
20°F
Outer Shell Material
20D Nylon Taffeta Shell With PFC-Free DWR
Liner Material
50D Polyester Taffeta Liner
Weight
2 lb 6.6 oz
Packing Dimensions
8 x 15.5 in
Stuff Sack Included
Preview
Kelty Cosmic 550 Dridown Sleeping Bag, Long/4-Degree
Title
Kelty Cosmic 0-Degree Sleeping Bag
Type of fill
600-Fill Power Hydrophobic DriDown™
Lower limit
0°F
Outer Shell Material
20D Nylon Taffeta Shell With PFC-Free DWR
Liner Material
50D Polyester Taffeta Liner
Weight
3 lb 12.8 oz
Packing Dimensions
10 x 21.5 in
Stuff Sack Included
Preview
Kelty Cosmic 40 Degree Down Sleeping Bag - Backpacking Camping Ultralight Compressible Sleeping Bag - Stuff Sack Included
Title
Kelty Cosmic 40-Degree Sleeping Bag
Type of fill
600-Fill Power Hydrophobic DriDown™
Lower limit
40°F
Outer Shell Material
20D Nylon Taffeta Shell With PFC-Free DWR
Liner Material
50D Polyester Taffeta Liner
Weight
1 lb. 12 oz
Packing Dimensions
7 x 12 in
Stuff Sack Included

Keep reading to discover how we rate the Kelty Cosmic and find out whether this could be the perfect sleeping bag to keep you cozy, comfy, and toasty on your outdoor adventures and camping trips: 

 

 


What is the Kelty Cosmic Down 20 Sleeping Bag?

The Cosmic 20-Degree Sleeping Bag is a 3-season mummy-style sleeping bag made by Kelty, an established brand in outdoor gear. This model of sleeping bags is one of the best-sellers in Amazon’s sleeping bag category and is often a top choice in ‘Best of’ overviews. That is exactly why we wanted to dive in deeper and discover more about this popular sleeping bag. Is it worth the praise, and why should you consider the Kelty Cosmic for your camping adventures? We’ll try to answer these questions, and more, in our in-depth product guide below.

 


What does the Temperature Rating mean?

When you start shopping for sleeping bags, a term that will always pop-up is the design’s temperature rating. Before we dive into our Kelty Cosmic review, we quickly want to recap what the temperature rating refers to, and why it matters.

The temperature rating is one of the most important buying factors for sleeping bags. Why? Because the very last thing you want is to invest in a sleeping bag, only to discover it’s not insulated enough to keep you cozy in cold weather conditions. That is where the temperature ratings come in, as this is the best measure to ensure a sleeping bag can handle the chill! 

The temperature rating indicates at what outdoor temperature a sleeping bag will keep you warm. Do keep in mind that the temperature rating is only an indication, not a guarantee. That said, it is a great guideline to gauge whether a sleeping bag is suited for your specific camping needs. For example, a 40°F temperature rating means the sleeping bag can be used in conditions as low as 40°F. Whilst a 0°F bag can be used in colder conditions, providing temperature doesn’t dip below 0°F, etc. 

Lower Limit versus Comfort Rating

It’s important to note that there are 4 different kinds of temperature ratings. The Lower Limit Rating is the most important of them all, but it helps to understand what the other temperature ratings mean. There are 4 temperature ratings commonly used when describing sleeping bags:

  • Upper Limit: the temperature where an adult male of the average body build is comfortable without sweating and needing to unzip or open the sleeping bag.
  • Comfort Rating: the temperature where an adult female of average build can sleep comfortably without being too warm or too cold.
  • Lower Limit: the temperature an adult male can sleep uninterrupted for 8 hours without cold or discomfort
  • Extreme Rating: the minimum temperature in which an adult woman can use the sleeping bag for 6 hours without the risk of lethal hypothermia.

Do note that a temp rating doesn’t take into account your personal body dimensions or metabolism. For example, if you have low body weight and fat percentage and/or suffer from poor blood circulation and cold hands and feet, a 20°F temperature rating may not keep you sufficiently warm in 20°F weather. For the best comfort, add an imaginary 20 degrees to the lower rating to find the ‘comfort spot’ – instead of merely looking at the comfort rating. 

Tip: To maximize the insulation a sleeping bag can offer, considering adding a sleeping pad or perhaps a sleeping bag liner to your setup. A sleeping pad (like the best-selling Therm-a-Rest NeoAir XTherm) can insulate you against chilly underground, whilst a liner can easily add several degrees of sleeping insulation to your bag. Plus, unlike natural down-fill sleeping bags, a separate sleeping bag liner can be machine-washed, which is extra hygienic.

 


 

Kelty Cosmic Sleeping Bag Review


 

Kelty Cosmic 20°F DriDown Sleeping Bag

Sale
Kelty Cosmic 20 Degree Down Sleeping Bag - Regular - Ultralight Backpacking Camping Sleeping Bag with Stuff Sack
  • The Kelty Cosmic 20 Degree sleeping bag is ideal for 3-season backpacking and camping. Water-resistant down insulation and an array of features make this sleeping bag a great combination of value and...

About

The Kelty Cosmic 20 Degree Sleeping Bag is an ultralight, natural down fill sleeping bag, ideal for backpacking and hiking. The Cosmic 20 model is recommended for three-season usage and comes with a temperature rating of 20° Fahrenheit. The sleeping bag’s comfort rating is nearly identical at 19° Fahrenheit: indicating it will keep you warm and comfortable in temperatures as low as 19°F. 

Dimensions

The Kelty Cosmic 20 DriDown Sleeping Bag is available in two sizes: regular and long. The regular-sized sleeping bag will fit campers up to 6ft (183cm) in length, whilst the long version accommodates campers up to 6ft 6 inches (198 cm). For this review, we’ll focus on the regular-sized Kelty Cosmic, as this model is most popular with campers. However, if you want some luxurious extra space or are a taller camper, the long-sized version is a great choice! The regular-size Kelty Cosmic 20 DriDown Sleeping Bag has a total packing weight of 2 lb 6.6 oz, of which 20.88 oz is pure down fill weight. When packed in its included stuff sack, the sleeping bag measures just 8 x 15.5 inches. 

Insulation

The Kelty Cosmic 20 DriDown Sleeping Bag is filled with 600-fill power hydrophobic DriDown™. What is DriDown™? Well, it’s a fancy term used by the brand to refer to the natural down-fill being waterproofed. Kelty describes it as: “Regular down is treated with a molecular level polymer to create a hydrophobic finish on each individual down plume. This finish allows DriDown™ to stay dry longer, loft better, and dry faster than untreated down, keeping you warmer in any environment.” Or, to put it more simply: DryDown™ is natural down that’s been treated to make it water-resistant. 

Do keep in mind that water-resistant coating does not mean the sleeping bag is 100% waterproof, however, it is much more water-resistant than sleeping bags with an untreated down fill. Another advantage of Dridown natural down fill is that it is quite lofty, adding a touch of luxury and comfort to camping adventures. Furthermore, this natural down is lightweight and highly compressible, which explains why the Kelty Cosmic has such favorable packing dimensions. 

Outer Shell and Lining

The Kelty Cosmic’s outer shell is made of soft 20-denier nylon taffeta with excellent durability. The interior of the sleeping bag is lined with 50-denier polyester taffeta. This quality polyester taffeta lining has a satin-like touch, which reminds us a bit of the feel of satin sheets. Silky and soft! It also means that you don’t have to add a separate sleeping bag liner for comfort, as the Kelty Cosmic already has you covered with its silky, non-scratchy lining.

Premium Perks

Besides high-quality DWR 600 fill Dridown insulation, a durable nylon shell, and a silky 50-denier polyester taffeta liner, the Kelty Cosmic 20 Sleeping Bag offers plenty of other premium perks. These include a special quilt-through construction for extra durability and a contoured baffle hood that can be cinched to eliminate cold spots. The silhouette is also equipped with an extra-roomy foot box, giving your toes some extra wiggle room. 

To help eliminate cold spots, the Kelty Cosmic is equipped with a draft collar and draft tube, which runs along the length of the anti-snag zipper. This special anti-snag design zipper is a dual-slider locking zipper, allowing for easy entry and exit of your sleeping bag. 

Lifetime warranty

If you’re looking for a reasonably priced, lightweight, comfy, and high-quality sleeping bag with premium perks: the Kelty Cosmic 20 Degree Sleeping Bag ticks all the boxes. When you buy from Kelty, you also know you’re getting an authentic product, guaranteed to live up to expectation. That is why Kelty issues a limited product warranty on its sleeping bags, which covers your purchase against any manufacturing defects for the lifespan of the product. Though some restrictions and conditions apply, this product warranty does entitle you to a free refund or replacement in most cases, giving you the peace of mind you can buy with confidence!

Pro

  • Ultralight (2.6 lbs)
  • Fantastic value-for-money
  • Superb weight-ratio
  • 600-fill power hydrophobic DriDown™
  • Durable 20D Nylon taffeta shell
  • Satin-like 50D polyester taffeta liner
  • Quilt-through construction
  • Thermal comfort cinched hood
  • Comfy, spacious foot box
  • Dual-sliding zipper with anti-snag design
  • Draft collar
  • Full-length draft tube
  • Stuff sack included

Con

  • Temperature rating not adequate for 4-season usage

 


 

Kelty Cosmic 0°F DriDown Sleeping Bag 

Kelty Cosmic 550 Dridown Sleeping Bag, Long/4-Degree
  • DriDown stays driers, keeps you warmer, and dries faster than regular down

About

Like the features and design of the Kelty Cosmic 20° Sleeping Bag – but want more insulation for cold weather camping? If the 20° temperature rating isn’t sufficient for you, consider the Kelty Cosmic 0-Degree Down Sleeping Bag. This model has similar features to the Kelty Cosmic 20 Down Sleeping Bag, but comes with a temperature rating of 0 degrees Fahrenheit, making it more equipped to keep you warm in extra-cold conditions. We’ll quickly recap the specs of the 0-degree Kelty Bag below, so keep reading to learn more! 

The Kelty Cosmic 0-Degree Down Sleeping Bag has a lower limit temperature rating of 0°F and a comfort rating of 2°F, making it suitable for 3-season usage – perhaps even 4-season in moderate climates. 

Dimensions 

The sleeping bag is available in two varieties: regular (fits up to campers 6′ in heigth) and long (fits campers up to 6’6″ in height). The regular-sized Kelty Cosmic 0-Degree Down Sleeping Bag weighs 3 lb 12.8 oz, of which 33.3 oz is natural down fill. The long version of the Kelty Cosmic 0-Degree weighs 4 lb .7 oz, of which 35.03 oz is natural down fill. When packed, the regular version measures 10 x 21.5 inches in stuffed size, the long option 10 x 22.5 inches. 

Insulation

The Kelty Cosmic 0-Degree Down Sleeping Bag is filled with 600 fill power DriDown™. This natural down has been treated with special polymers, which has created a water-resistant coating on each plume. The advantage is that DriDown can stay dry longer, and dry faster, than untreated down. This means that even in damp and wet conditions, the Dridown fill does not lose its insulation properties, and can still keep you warm. 

Outer Shell and Lining

The outer shell of the Kelty Cosmic 0-Degree Down Sleeping Bag is made of durable 20-denier nylon taffeta. The interior lining of the sleeping bag is made of 50-denier polyester taffeta that feels smooth and silky to the touch and has great durability.

Premium Perks

The Kelty Cosmic 0-Degree Down Sleeping Bag offers more than ample protection against cold weather, thanks to its high-quality design perks. For example, the sleeping bag has a draft tube that runs along the full length of the anti-snag zipper, preventing warmth from escaping during the night. The design also comes with a baffle draft collar, helping reduce heat loss from the top of the bag and prevent cold spots.

Other premium perks include handy pad loops that allow you to attach your sleeping bag to a sleeping pad, minimizing the risk of rolling and suddenly finding yourself on the icy ground in the middle of the night. We also like that the Kelty Cosmic 0-Degree Sleeping Bag comes with a handy stash pocket to keep smaller personal belongings, for example, your phone, within easy reach.

If you want premium down-fill comfort and warmth, without paying the jackpot, the Kelty Cosmic 0-Degree Down Sleeping Bag is simply a great choice for cold weather camping. 

Pro

  • 0°F/ -18°C temperature rating
  • Great value-for-money
  • 600-fill power DriDown™
  • Water-resistant down-fill coating
  • Soft polyester taffeta lining
  • Durable 20D nylon outer shell
  • Baffle draft collar
  • Quilt-through construction
  • Dual-sliding zipper with anti-snag design
  • Draft collar & draft tube
  • Stuff sack included

Con

  • Slightly more expensive
  • Not the most lightweight (4 lbs)
  • Not the best warmth-to-weight ratio

 


 

Kelty Cosmic 40°F DriDown Sleeping Bag

Kelty Cosmic 40 Degree Down Sleeping Bag - Backpacking Camping Ultralight Compressible Sleeping Bag - Stuff Sack Included
  • The Kelty Cosmic 40 Degree sleeping bag is ideal for 2-season backpacking and camping. Water-resistant down insulation and an array of features make this sleeping bag a great combination of value and...

About

The Kelty Cosmic 40 Degree DriDown Sleeping Bag is a lightweight sleeping bag, ideal for fair weather camping. The ultralight Kelty Cosmic 40 Degree Sleeping Bag weighs just 1 lb 9.7 oz (regular-size), which is an outstanding weight-ratio that is ideal for backpacking adventures. It truly is one of the lightest mummy bags on the market, which has made it a best-seller amongst backpackers. The Kelty Cosmic 40 Degree Down Sleeping Bag has a comfort rating of 48°F and a lower limit of 40°F. We wouldn’t recommend this model for those campers that live in cold weather climates. However, if you only venture out in the summertime, and consider yourself a fair-weather camper, this sleeping bag’s 40-Degree temperature rating could be just what you need to stay comfy without overheating! 

Dimensions

The Kelty Cosmic 40 Degree DriDown Sleeping Bag is available in two options: regular-sized and long. The regular-sized version fits campers up to 6′, the long up to 6’6″. The sleeping bag includes a stuff sack, and can be packed down to a bundle that measures approximately 7″ x 12″. 

Insulation

This backpacking sleeping bag features Kelty’s special 600-fill power hydrophobic DriDown™ insulation. What does this entitle? Well, simply put, it means that the down used has been treated with polymers, creating water-repellent finish on each plume. Or, even simpler: waterproof DriDown™ can stay dry longer, loft better, and dry faster than untreated down, keeping you warm and dry in any environment. Do note that this 40-Degree sleeping bag has less down fill than the 20-Degree model, making it less lofty and luxurious – but still more than capable of keeping you comfy at night.

Outer Shell and Lining

The outer shell of this 40-Degree Kelty Cosmic model is a soft, butter-like 20-denier nylon taffeta with excellent durability. The inner lining, just like the 0-Degree and 20-Degree model, is made of 50-denier polyester taffeta. This material has a satin-like, soft feel – making a separate sleeping bar liner redundant. 

Premium Perks

Other high-end perks of the Kelty Cosmic 40 Degree Down Sleeping Bag are a quilt-through construction for superb durability, a thermal-comfort hood that can be cinched with drawcords to eliminate drafts and cold spots, and a ‘natural-fit’ foot box. This backpacking-friendly, lightweight sleeping bag also comes with a dual-slider, locking zipper with anti-snag design. Plus a draft collar and draft tube along the length of the anti-snag zipper to prevent heat loss and make cold spots a thing of the past. 

Pro

  • Ultralight (1 lb 9.7 oz)
  • Great value-for-money
  • Excellent weight-ratio
  • 600-fill power hydrophobic DriDown™
  • Durable 20D Nylon taffeta shell 
  • Satin-like 50D polyester taffeta liner
  • Quilt-through construction
  • Thermal comfort cinched hood
  • Natural-fit foot box
  • Dual-sliding zipper with anti-snag design
  • Draft collar & draft tube
  • Stuff sack included

 Con

  • Not suited for cold weather camping
  • Not as lofty as the 0-Degree or 20-Degree model 

 


 

Verdict

After reviewing the Kelty Cosmic Sleeping Bag in much detail, and browsing through hundreds of customer reviews on Amazon and other platforms, our verdict is clear: this sleeping bag is worth the money! When you compare the Kelty Cosmic to three-season sleeping bags in the same price category, it becomes abundantly clear this model offers a lot of bang for your buck. Whether you choose the 0°F, 20°F, or 40°F option: each is an excellent value-for-money buy.

For mid-budget pricing, you get high-end perks and durability. The Kelty Cosmic features a high-quality natural down fill with a durable water-repellent coating (DWR). Even when it gets wet or damp, this hydrophobic-treated down does not lose its insulation properties: keeping you cozy all night long. Furthermore, the mummy-style silhouette is enhanced with various clever design elements to beat the chill, including a draft tube, draft collar, anti-snag zipper, and a hood that can be cinched with drawstrings to eliminate cold spots around the head. In addition to keeping you warm, the Kelty Cosmic also keeps you cozy with its soft and silky 50-denier polyester taffeta lining.

If you’re looking for a reasonably-priced sleeping bag with lots of lofty comfort, warmth, and convenience: the Kelty Cosmic is simply one of the best buys you’ll find. Confirmed by us, and by thousands of other campers, backpackers, and outdoor enthusiasts. It is worth the hype! Plus, a limited lifetime warranty by Kelty covers your purchase on any manufacturing defects, ensuring you get a top-grade product that lives up to (and exceeds) expectations. 

 

Recap

Preview
Kelty Cosmic 20 Degree Down Sleeping Bag - Regular - Ultralight Backpacking Camping Sleeping Bag with Stuff Sack
Kelty Cosmic 550 Dridown Sleeping Bag, Long/4-Degree
Kelty Cosmic 40 Degree Down Sleeping Bag - Backpacking Camping Ultralight Compressible Sleeping Bag - Stuff Sack Included
Title
Kelty Cosmic 20-Degree Sleeping Bag
Kelty Cosmic 0-Degree Sleeping Bag
Kelty Cosmic 40-Degree Sleeping Bag
Type of fill
600-Fill Power Hydrophobic DriDown™
600-Fill Power Hydrophobic DriDown™
600-Fill Power Hydrophobic DriDown™
Lower limit
20°F
0°F
40°F
Outer Shell Material
20D Nylon Taffeta Shell With PFC-Free DWR
20D Nylon Taffeta Shell With PFC-Free DWR
20D Nylon Taffeta Shell With PFC-Free DWR
Liner Material
50D Polyester Taffeta Liner
50D Polyester Taffeta Liner
50D Polyester Taffeta Liner
Weight
2 lb 6.6 oz
3 lb 12.8 oz
1 lb. 12 oz
Packing Dimensions
8 x 15.5 in
10 x 21.5 in
7 x 12 in
Stuff Sack Included
Preview
Kelty Cosmic 20 Degree Down Sleeping Bag - Regular - Ultralight Backpacking Camping Sleeping Bag with Stuff Sack
Title
Kelty Cosmic 20-Degree Sleeping Bag
Type of fill
600-Fill Power Hydrophobic DriDown™
Lower limit
20°F
Outer Shell Material
20D Nylon Taffeta Shell With PFC-Free DWR
Liner Material
50D Polyester Taffeta Liner
Weight
2 lb 6.6 oz
Packing Dimensions
8 x 15.5 in
Stuff Sack Included
Preview
Kelty Cosmic 550 Dridown Sleeping Bag, Long/4-Degree
Title
Kelty Cosmic 0-Degree Sleeping Bag
Type of fill
600-Fill Power Hydrophobic DriDown™
Lower limit
0°F
Outer Shell Material
20D Nylon Taffeta Shell With PFC-Free DWR
Liner Material
50D Polyester Taffeta Liner
Weight
3 lb 12.8 oz
Packing Dimensions
10 x 21.5 in
Stuff Sack Included
Preview
Kelty Cosmic 40 Degree Down Sleeping Bag - Backpacking Camping Ultralight Compressible Sleeping Bag - Stuff Sack Included
Title
Kelty Cosmic 40-Degree Sleeping Bag
Type of fill
600-Fill Power Hydrophobic DriDown™
Lower limit
40°F
Outer Shell Material
20D Nylon Taffeta Shell With PFC-Free DWR
Liner Material
50D Polyester Taffeta Liner
Weight
1 lb. 12 oz
Packing Dimensions
7 x 12 in
Stuff Sack Included
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Samantha Bos

Samantha Bos

Samantha is an avid outdoor enthusiast who loves exploring the great unknown. She’s traveled all across the globe to sample nature’s delights. And her travels have taken her to all corners of the world: from hiking the famous Inca Trail in Peru to ice-hiking on glaciers in Alaska. Besides hiking, Samantha likes to challenge herself with all kinds of outdoor activities. She doesn’t shy away from testing her limits. For example, navigating Grade 5 rapids whilst whitewater rafting in New Zealand, and avoiding close-encounters with bird-eating spiders and poisonous plants in the Australian rainforest. Currently based in Manhattan, New York, she’s traded in the real jungle for an urban jungle. But she tries to get out and explore nature in the surrounding Hudson Valley, Catskills, and Harriman State Park areas as often as she can. She shares her knowledge of hiking, backpacking, and outdoor activities in handy ‘Best of’ overviews. Bundling the best-value, top-rated products that will no doubt make every reader a ‘happy camper’.