Kelty Cosmic Synthetic 20 review

The Cosmic Synthetic 20 is the cheapest way into a 20°F bag on this list. Kelty rates it at 20°F / -7°C and fills it with 31.4 oz of CirroLoft ECO synthetic insulation made from recycled fibers. The Regular weighs 2 lb 13 oz in total and packs into a 9.5 by 18 inch compression stuff sack, so it is heavier and much bulkier than the Cosmic Down 20, which costs $80 more. The shell is recycled 20D nylon with a PFAS-free DWR and the liner is a soft taffeta. Kelty includes the same draft collar, full-length draft tube, dual locking sliders, zippered stash pocket and roomy footbox as on its down bag. Synthetic fill keeps working when damp, which helps on humid or rainy trips. The 20°F figure is a single rating rather than ISO comfort and limit numbers, so plan on comfort a little above that. At $109.95 for the Regular it is a sensible first bag for car camping and short backpacking trips.

Who it is for

new campers who want a 20°F bag for about $110

Price

$109.95 for the Regular at the Kelty store when checked; Long $119.95.

$109.95 Size : Regular
Quoted from the vendor pricing page on November 12, 2026.

Key features

• 20°F / -7°C temperature rating
• Recycled CirroLoft ECO synthetic insulation
• 2 lb 13 oz total weight for the Regular
• Compression stuff sack, 9.5 by 18 inches
• Recycled 20D nylon shell with PFAS-free DWR

Strengths and weaknesses

• Strength: Lowest price on this list at $109.95
• Strength: Synthetic fill tolerates damp better than down
• Strength: Zippered stash pocket and expanded footbox
• Weakness: Packs to 9.5 by 18 inches, large for backpacking
• Weakness: 2 lb 13 oz for a 20°F rating, heavier than the Cosmic Down 20
• Weakness: Only Regular and Long sizes

Key facts

• Price: $109.95 (Regular)
• Temperature rating: 20°F / -7°C
• Weight: 2 lb 13 oz (Regular)
• Insulation: CirroLoft ECO synthetic
• Fits up to: 6 ft (Regular)

Where it ranks

Kelty Cosmic Synthetic 20 is No. 9 in our Best Sleeping Bags verdict.