Kelty Cosmic 20 Review
Real Down, Real Cheap

Down sleeping bags are expensive.  Most down sleeping bags are usually in the $200-$400 range so to cut down on costs, many backpacks will buy synthetic down sleeping bags instead.  Synthetic down has a couple of qualities that make it inferior to real down:

  • Synthetic down will be heavier than real down.
  • Synthetic down sleeping bags don't pack down as small as real down.
  • Synthetic down bags lose some of their insulating capability every time they get compressed.

So when Kelty came out with a 20 degree sleeping bag with real down in the $150 price range, it was a game changer, coming in at less than half the price of other down sleeping bags on the market.

Building out a full backpacking gear kit can be expensive, so being able to save hundreds of dollars on a sleeping bag is a huge deal and is the reason why we recommend the Kelty Cosmic 20 as our #1 sleeping bag choice for most people.

Kelty Cosmic 20 Review Summary


  • Real down sleeping bag for under $200.
  • Easy to compress down and pack.
  • Warm even down to 20-30 degrees.


  • A little heavier than other down bags due to the low fill count.​​​​
  • Zipper stops at the knees; can be annoying to get in and out.
  • Included stuff sack doesn't compress very much.

Great for new backpackers or anyone looking to save some money, the Kelty Cosmic Down 20 Sleeping Bag is the best choice for anyone on a budget.

This isn't the smallest, warmest, cheapest, or easiest bag to use.  BUT, it is the best combination of all 4 factors.  Kelty does a great job of striking a balance between size, warmth and price making this our top pick for budget down sleeping bag.

How Warm is the Kelty Cosmic 20?

The most important job for a sleeping bag is to keep you warm and the Kelty Cosmic 20 does a great job.  All sleeping bags have a temperature rating and the Kelty Cosmic 20 has a rating of 20 degrees F (hence the 20 in the name).  

However, that 20 degree rating is what I call the survival rating, or what temperature you could sleep through overnight and survive.  

That doesn't mean if you use this bag in 15 degree weather you're going to die; you'll just need to bundle up with some extra layers or you'll probably be pretty cold all night.

The comfort rating for this bag is 30 degrees F.  This is the most important temperature rating to look at when shopping for a sleeping bag.  

This is the temperature where a male user would be comfortable during the night sleeping in a light base layer, like a t shirt and boxers.

The Kelty Cosmic 20 lives up to both of these ratings.  At 30 degrees and above you'll be very toasty and comfortable.  

This makes it a great sleeping bag for anyone looking to get a real down bag that will be used for 3 season camping.  

This bag is not for anyone who wants to do winter camping in temperatures below 10-20 degrees.  For that you'd need to look into something like the Kelty Cosmic 0 which has a 0 degree temperature rating and is specially made for cold weather camping.  You can check out the Kelty Cosmic 0 here.

Kelty Cosmic Down 20 Specifications


Short - 2 lbs 6 oz

Regular - 2 lbs 9 oz

Long - 2 lbs 13 oz

User Height

Short - 5' 6"

Regular - 6' 0"

Long - 6' 6"

Packed Size

Short - 8" x 13"

Regular - 8" x 14"

Long - 8" x 14"

Temperature Rating

30 degrees F (comfort)/ 20 degrees F (survival)

Fill Rating

600 Fill DriDown

Kelty Cosmic 20 Weight and Size

Next up after warmth is weight and size.  If you're mostly car camping, this won't be a big consideration for you, but that doesn't mean you should ignore it!

If you're not concerned with weight or space then you'd be better off with a cheaper bag that uses synthetic down.  Don't spend the extra money on a real down sleeping bag if you don't need it.

If you're going to be backpacking, then cutting every last ounce and packing everything down as small as possible is crucial to be able to fit everything in your pack.  

The Kelty Cosmic 20 comes in 3 different sizes; short, regular and long.  Which bag you should buy depends on how tall you are.

The short sleeping bag is meant for people that are 5' 6" and smaller.

The regular sleeping bag is for people 6' 0" and smaller.

The long sleeping bag is for people 6' 6" and smaller.

If you're even 1" over any of these cut offs, I'd recommend getting the next size up.  There's nothing worse than buying a sleeping bag only to find your head smushed on one end and your toes crushed on the other end.

But you also don't want to just buy the largest size available.  Sleeping bags are specially designed to have extra insulation in the foot area since that is usually the part of your body that gets the coldest at night.  You want the bag to be comfortable but you also want to make sure your feet are going to be in the correct spot in the sleeping bag to stay nice and warm.

The packed down size of this sleeping bag is roughly 8" x 14".  The short bag is slightly smaller when it's compressed but not by much.

The weight does differ slightly between models.  The short sleeping bag weighs 2 lbs 6 oz; the regular size is 2 lbs 9 oz; and the long is 2 lbs 13 oz.  Those couple of ounces may not sound like a lot but going from the short bag to the long bag adds 7 oz which is an 18% increase in weight!

What Comes with the Kelty Cosmic 20?

The Cosmic 20 comes with a stuff sack which is not to be confused for a compression sack.

Some sleeping bags come with a really nice compression sack that will squish the sleeping bag down incredibly small and let you stick it away in your backpack.

But the Cosmic 20 only has a stuff sack which offers almost no compression.  If you're looking for a way to pack this sleeping bag down as small as possible you'll need to buy an aftermarket compression sack like the Alps compression sack.

The Kelty Cosmic 20 comes with a stuff sack that does the job, but if you're looking for extra compression then you'll need to pay a little bit more and get a nice compression sack like the one shown here from Alps Mountaineering.

Final Verdict

The Kelty Cosmic 20 is the best choice for anyone who wants a real down sleeping bag.  No other sleeping bag on the market can compete at this price point.

If you're not a backpacker and not as concerned with space or weight, then you might want to go with something a little cheaper like a synthetic down sleeping bag. 

Our recommendation for that would be the Coleman North Rim sleeping bag that has a 0 degree temperature rating and costs less than half as much as the Kelty Cosmic 20.

If you're looking for a sleeping bag that can handle lower temperatures then our recommendation would be the Kelty Cosmic 0 which is nearly identical to the Cosmic 20 except it can handle temperatures down to 0 degrees F.

The Coleman North Rim (left) is less than $50 and has a 0 degree temperature rating but uses synthetic down and does not pack down as small as the Kelty Cosmic 20.

The Kelty Cosmic 0 (right) costs about 50% more than the Cosmic 20 but can handle much colder temperatures.  If you're going to be backpacking during the winter, this is the bag you should go with.