Kelty
Kelty Cosmic Down 20 (Regular)
Where it fits
- Also works for
- Backpacking and wild camping
- Not for
- Winter mountain
Why these labels
- Backpacking and wild camping: Light to carry: 1.1 kg
- Winter mountain: Comfort rating 0 °C: too cold for winter nights
From the maker's stated use and the published specs.
- Summer wild camp: 5/10 UK, roughly May to September, nights above about 8 °C, sheltered pitches.
- Three-season hills: 6/10 UK hills in spring and autumn. Wind, rain, and nights near freezing.
- Winter camp: 4/10 UK winter or high ground. Below freezing, strong wind, possibly snow. Capped at 4: needs warmth 9+ (comfort -5 °C or colder).
- Weight: 6/10 How much it adds to your pack, compared with the whole market.
Comfort 0 °C, limit -6 °C (ISO 23537).
Spring to autumn camping on lower ground and campsites when you want real down on a tight budget
- Comfort
- 0 °C
- Limit
- -6 °C
- Fill
- 550 fill down
- Weight
- 1.11 kg (Regular)
Packed size 10.4 L, 33 cm long and 20 cm across Compare with a 2-litre bottle
About as long as a 2-litre bottle and about twice as wide. Drawn to scale.
Where to buy
Absolute Snow £154.95 In stock. Free delivery.
View at shop: Absolute SnowDecathlon UK £170 In stock. Sold by Twist Distribution on Decathlon's marketplace; delivery set by the seller.
View at shop: Decathlon UKPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Warmth
From maker's figures 7/10How cold a night you can sleep comfortably through. 7: Better than most.
A UK shop spec table copying Kelty's data gives an ISO comfort of 0 °C (limit -6 °C), which sits in the -4.9 to 0 °C band; Treeline quotes the same ISO figures. Kelty's own page shows only the -7 °C name rating. Testers found it comfortable only down to about 0 °C, so the '20' is not a comfort figure.
Room inside
From reviews 5/10How much room to move, bend your knees and sleep on your side. Roomier is comfier. 5: Does the job. Average for wild-camping gear.
Reviewers split. One finds it roomy for a mummy, two find the narrow midsection restrictive for side sleepers and restless sleepers. Fine for back sleepers.
Reviewers disagree on this.
Weight
From maker's figures 6/10How much it adds to your pack. 6: A bit better than average.
Kelty's 1,106 g for the Regular sits in the 1,000–1,299 g band.
Packed size
From maker's figures 4/10How much room it takes in your rucksack. 4: A bit below average.
Stuff sack is 20 x 33 cm: 3.1416 x 10 x 10 x 33 = 10,367 cm³, so 10.4 L, in the 9–12.9 L band (reviewers quote 10.7 L for the same sack).
What reviewers say (out of 10)
Ratings marked * are from reviews and are not part of the trip score. They are reviewers' scores, not our own measurements. How we score
Comfort to sleep in*
Reviewers' average 6/10How comfy the shape, hood and fabric feel; not the temperature rating.
3 reviews on comfort, e.g. "severe taper below the belt".
Reviewers disagree on this.
Zip*
Reviewers' average 8/10How smoothly the zip runs without snagging.
3 reviews on the zip, e.g. "zippers also feel solid and glide smoothly without any noticeable snagging issues".
In short
Good for
- Spring to autumn camping on lower ground and campsites when you want real down on a tight budget
- Short overnight backpacks where a heavier, bulkier bag is not a problem
- Anyone who wants a tough bag that can take some rough treatment
Strengths
- Fabrics thicker than on ultralight bags and a smooth two-way zip that testers found tough
- Zipped inside pocket for a head torch or phone, and a hood that fits a small pillow
Weaknesses
- The '20' in the name is the limit rating: reviewers found it comfortable only to about 0 °C, so cold sleepers should treat it as a 0 °C bag
- Heavy and bulky for a down bag because the 550 fill power needs more down for the warmth; not a good pick for long walks
- Narrow through the hips and legs for some people, especially side and stomach sleepers
- The maker doesn't say the down is water-repellent treated and one tester says it isn't, so keep it dry; reviewers disagree on this
- We found only two usable opinions each on damp performance and durability, so those two are estimates, not reviewed scores
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.
ShowHide sources (6)
- Kelty: Cosmic Down 20 Sleeping Bag
- Absolute Snow: Kelty Cosmic Down 20 Regular (UK shop spec table with ISO ratings; Kelty's own page gives only the -7 °C rating)
- Better Trail: Kelty Cosmic Down 20 Sleeping Bag Review
- CleverHiker: Kelty Cosmic Down 20 Review
- Treeline Review: 50 nights testing the Kelty Cosmic 20 sleeping bag
- Backpackers.com: Kelty Cosmic Down 20 review