Head-to-head · Best 0 Degree Sleeping Bags

Feathered Friends Ibis ES 0 vs Therm-a-Rest Parsec 0F/-18C

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

Feathered Friends Ibis ES 0 comes out ahead by a narrow margin (4.6 vs 4.3). The gap is mostly about Winter campers in cold, wet, or condensation-prone conditions who want a conservatively rated bag and will pay top dollar for a waterproof shell. — read the strengths below before deciding.

Higher ratedRanked #1 in Best 0 Degree Sleeping Bags

Feathered Friends Ibis ES 0

4.6

2 sourcesall derived$859as of Aug 1

The Ibis ES 0 pairs 900+ fill power goose down with a waterproof-breathable Pertex Shield EX shell, which makes it the bag to beat for cold, damp winter conditions. Feathered Friends rates conservatively, so its 0°F sits closer to a true comfort rating than a survival limit. It is the widest of the brand's zero-degree bags, and also among the heaviest here at 3 lb 2 oz.

Strengths

— 900+ fill power goose down, the highest-loft insulation in this group
— Waterproof-breathable Pertex Shield EX shell handles condensation and damp tents
— Conservative 0°F rating means real-world comfort at the stated temperature

Watch-outs

— Heavy for a 0°F down bag at 3 lb 2.4 oz for the regular
— List price of $859 puts it at the top of the category
— Waterproof shell adds weight and slightly less breathability than open nylon

$859 · Buy at featheredfriends.com Full review →

Ranked #4 in Best 0 Degree Sleeping Bags

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

4.3

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

$480 · Buy at spokex.com Full review →

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

Feathered Friends Ibis ES 0

The highest-loft and most weather-resistant bag here thanks to 900+ fill and a Pertex Shield EX shell, rivaling the Western Mountaineering Kodiak MF for warmth but heavier than it, the Mountain Hardwear Phantom 0, the Therm-a-Rest Parsec 0F and the Sea to Summit Spark 0F.

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.

Specs side-by-side

Spec	Feathered Friends Ibis ES 0	Therm-a-Rest Parsec 0F/-18C
Temperature Rating	0°F (-17.7°C) comfort	0°F limit / 14°F comfort (ISO)
Fill Power	900+ goose down	800 Nikwax Hydrophobic goose down
Fill Weight	1 lb 15.2 oz (884 g)	—
Total Weight	3 lb 2.4 oz (1429 g)	2 lb 6 oz (1.09 kg)
Shell	Pertex Shield EX waterproof-breathable	—
Shoulder Girth	59 in	—
Packed Size	17 L	—
Origin	Made in Seattle, USA	—
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
Material	—	Nylon

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