Kelty
Kelty Cosmic Down 20
No citable owner-review average published for this one, so no stars.
The bag most people's first down bag is, and reasonably so: 550-fill DriDown, an ISO comfort figure of 31 °F, a semi-rectangular cut with room to move, and $190. Five-fifty fill is low, which means the warmth comes from bulk rather than quality — 16.4 ounces of down in a 39-ounce bag that packs big. As an entry into down camping it is hard to argue with; as a backpacking bag it is beaten on every axis by bags costing twice as much, which is exactly what you would expect.
Label against lab
Sold as a 20 °F bag; its ISO 23537 comfort rating is 31 °F, which is 11 °F warmer than the name suggests. Plan around the comfort figure, not the label. Why the gap exists
At that temperature the pairing table wants at least an R 3 pad underneath it.
Specifications
Highlights
Features
- ISO or EN rated
- Hydrophobic down
- RDS down
- Draft collar
- Full-length zipper
- Recycled fabric
- Stash pocket
What it does well
- Publishes both ISO figures — comfort 31 °F, limit 21 °F — at a price where most competitors publish neither.
- Semi-rectangular cut with a wide footbox; far less confining than a true mummy.
- DriDown is hydrophobic-treated and RDS-certified even at this price point.
- $190 for a real down bag, and Kelty's trapezoidal baffles keep the fill from migrating.
What it costs you
- 550-fill down means the loft comes from volume: 39 ounces and a large packed size.
- The 31 °F comfort figure is eleven degrees off the 20 in the name.
- Kelty doesn't publish shoulder girth.
- Only the Regular's figures were verifiable; the Short and Long weights are known but their prices are not, so the size run is not tabulated here.
Those two lists are drawn from Kelty’s published specifications and from reviews that measured them. They are not owner sentiment — anything owners said appears under its own heading below.
What owners say
Distilled from owner discussions and long-term published reviews, not from anything measured here.
The Cosmic is the bag people are pointed at when the budget is tight and they want down. The discount culture around it is part of its identity — owners quote the sale price to each other and treat list price as theoretical.
The most interesting thread in owner discussion is about whether the bag has changed. An owner with an eight-year-old example says the comfort rating has always felt true to them; another notes that fill has been reduced in newer versions and the rating adjusted accordingly. Both can be right, and it means old recommendations should be read with the year in mind.
There is also live owner disagreement about whether Kelty lab-tests this bag at all. Published sources give comfort and limit figures; at least one owner asserts the Cosmic is not tested to the standard. That disagreement is itself worth knowing, and this site's figures come from published specifications rather than from the packaging.
What owners like
- Owners find it heavily discounted often enough that the sale price, not the list price, is what people quote to each other.
- An owner with an eight-year-old example reports the comfort rating feeling genuinely true at 20 °F for them, which is a long-term endorsement.
- It gets named repeatedly as the sensible first down bag, and the women's version specifically for budget buyers.
- Kelty as a brand is described as solid and affordable, which owners mean as a compliment rather than a hedge.
Common complaints
- Owners report that fill has been reduced in newer versions and that the comfort rating has moved with it, so an old owner's experience may not describe a new bag.
- There is genuine owner disagreement about whether Kelty publishes lab-tested figures for this bag, which is the sort of confusion that a clearly-stated standard would end.
- 550-fill down means it is bulky, and owners trying to fit a kit into a small pack are told to look elsewhere.
- Owners warn that the advertised packed size is optimistic and recommend a compression sack.
Questions owners ask
Has the bag changed over the years?
Is it lab-rated?
How bulky is it?
Kelty Cosmic Down 20, head to head
Others in the same band
More from Kelty →A synthetic mummy with an ISO comfort rating of 24 °F for $189, built entirely from recycled fabric and fill. That comfort figure is the interesting part: at four degrees off its own name it is one of the most honestly labelled bags here, and it is warmer at the comfort end than several down bags costing three times as much. The price is three and a half pounds and a stuff sack the size of a football, which is why this is a car-camping and canoe-trip bag rather than a backpacking one.
Best for: Damp-weather camping on a budget
Full spec sheet
NEMO
NEMO Tempo 20
NEMO's entry synthetic bag: the Spoon shape and the Thermo Gills in a heavier 50-denier shell with a lower grade of Zerofiber, at $170. The 50D fabric is the real difference — it is a much tougher bag than the Forte, which matters more in a campground and on a car-camping trip than the 58-ounce weight does. Published ISO lower limit of 21 °F, honest for a bag with a 20 on the label.
Best for: Campground and car-camping trips in a wet climate
Full spec sheet
Big Agnes
Big Agnes Lost Ranger 3N1 15
Two bags that nest: an outer 15-degree shell and an inner lighter bag, usable separately for summer, together for winter, or as a single mid-weight bag in between. It is the most flexible sleep system in this catalogue and also the heaviest way to buy that flexibility — 44.5 ounces for the pair. For a family or a couple who camp from June through October and want one purchase to cover it, the argument holds. For a backpacker it does not.
Best for: One purchase covering summer through shoulder season
Full spec sheet