Verdict
Head-to-head · Best 0 Degree Sleeping Bags

Therm-a-Rest Parsec 0F/-18C vs Western Mountaineering Kodiak MF

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

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The short answer

Western Mountaineering Kodiak MF comes out ahead by a narrow margin (4.3 vs 4.4). The gap is mostly about Cold-weather campers and side sleepers who want the most reliable 0°F warmth and room to move, and don't mind paying a premium. — read the strengths below before deciding.

Therm-a-Rest Parsec 0F/-18C
Ranked #4 in Best 0 Degree Sleeping Bags
Therm-a-Rest Parsec 0F/-18C
3 sourcesall derived$480as of Aug 1

The Parsec 0F is the warmth-to-weight standout of this group: at 2 lb 6 oz it is one of the lightest true 0°F down bags you can buy. Advnture and The Trek both rate it 4.5/5, praising the loft and the value, while a cold-weather test by Captain Berz put the honest floor closer to 5°F than 0°F. It uses 800-fill down rather than the 850 to 900 fill of the premium bags here, and it costs far less than they do.

Strengths
  • Outstanding warmth-to-weight ratio at just 2 lb 6 oz for a 0°F bag
  • 800-fill Nikwax Hydrophobic Down resists moisture and dries faster
  • Box-baffled, body-mapped 60/40 down distribution puts insulation where it counts
Watch-outs
  • Still expensive at $490-$570 in absolute terms
  • One real-world cold test recommended a 5°F practical floor, not 0°F
  • Cold sleepers and women may find the honest comfort closer to 10°F
Western Mountaineering Kodiak MF
Higher ratedRanked #3 in Best 0 Degree Sleeping Bags
Western Mountaineering Kodiak MF
2 sources1 derived$795as of Aug 1

The Kodiak MF is the warmest 0°F bag most reviewers have ever tested, beating its rating with a roomy, side-sleeper-friendly cut. OutdoorGearLab consistently names it their top winter pick and found it performed more like a -20°F bag than a 0°F one. The trade-off is a list price near $900 and a wide cut that costs some warmth-to-weight efficiency against narrower mummies.

Strengths
  • Tested warmer than its 0°F rating; held testers to roughly -10°F with light layering
  • 1.88 lb of 850+ fill goose down with continuous baffles you can shift top-to-bottom
  • Wide-cut mummy with generous shoulder, hip and footbox room for side sleepers
Watch-outs
  • List price near $895-$950 is among the highest in the category
  • Wide cut adds dead air space, so it is not the most weight-efficient 0°F option
  • Continuous baffles can shift down underneath you if not redistributed

Derived means the reviewer published no score, so one was inferred from their written verdict. Everything else is a number the publisher printed. How we rank.

How they stack up

Therm-a-Rest Parsec 0F/-18C

The lightest and best-value true 0°F bag here, beating the Western Mountaineering Kodiak MF, Feathered Friends Ibis ES 0 and Mountain Hardwear Phantom 0 on warmth-to-weight and price, though it uses lower 800-fill down than the Kodiak and Ibis and is heavier than the Sea to Summit Spark 0F.

Western Mountaineering Kodiak MF

The roomiest and warmest bag here, beating the Mountain Hardwear Phantom 0 and Therm-a-Rest Parsec 0F on real-world warmth and the Feathered Friends Ibis ES 0 on cut width, but it is heavier and pricier than the lighter Sea to Summit Spark 0F.

Specs side-by-side

SpecTherm-a-Rest Parsec 0F/-18CWestern Mountaineering Kodiak MF
Temperature Rating0°F limit / 14°F comfort (ISO)0°F (-18°C)
Fill Power800 Nikwax Hydrophobic goose down850+ goose down
Total Weight2 lb 6 oz (1.09 kg)2 lb 12 oz
BafflesBox-baffled, 60/40 body-mapped
LengthRegular 80 in
ExtrasPad straps, external quilt loops
ZipperTwo-way YKK side zip
WarrantyLimited lifetimeLifetime craftsmanship
MaterialNylongoose-down
Fill Weight1.88 lb (30 oz)
Shell20D MicroLite XP nylon
CutWide mummy, continuous baffles
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