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.

The short answer

Western Mountaineering Kodiak MF comes out ahead by a narrow margin (4.5 vs 4.6). 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.

Ranked #3 in Best 0 Degree Sleeping Bags

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

4.5

$530

The Parsec 0F is the warmth-to-weight champion of this group, at 2 lb 6 oz one of the lightest true 0°F down bags you can buy. Reviewers across The Trek, Advnture, and SectionHiker praise its loft and value, though it uses 800-fill down and at least one cold-test reviewer found its honest comfort floor closer to 5°F than 0°F. At around $530 it badly undercuts the premium bags here.

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

$530 · Check Price on Amazon Full review →

Higher ratedRanked #1 in Best 0 Degree Sleeping Bags

Western Mountaineering Kodiak MF

4.6

$895as of Jun 7

The Kodiak MF is the warmest 0°F bag most reviewers have ever tested, exceeding 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 versus 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

$895 · Check Price on Amazon Full review →

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

Spec	Therm-a-Rest Parsec 0F/-18C	Western Mountaineering Kodiak MF
Temperature Rating	0°F limit / 14°F comfort (ISO)	0°F (-18°C)
Fill Power	800 Nikwax Hydrophobic goose down	850+ goose down
Total Weight	2 lb 6 oz (1.09 kg)	2 lb 12 oz
Baffles	Box-baffled, 60/40 body-mapped	—
Length	Regular 80 in	—
Extras	Pad straps, external quilt loops	—
Zipper	Two-way YKK side zip	—
Warranty	Limited lifetime	Lifetime craftsmanship
Fill Weight	—	1.88 lb (30 oz)
Shell	—	20D MicroLite XP nylon
Packed Size	—	9 x 18 in
Cut	—	Wide mummy, continuous baffles

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