Review: Mountain Hardwear Phantom 30 Sleeping Bag

Ultralight Sleeping Bag
Mountain Hardwear Phantom 30
$450, 1 lb. 6 oz./624g (unisex regular, 72-inch)
Sizes: unisex short ($440), regular, long ($480)

Look at specs when shopping for a high-quality, ultralight, three-season sleeping bag and you might quickly trim your short list to about five models, all at basically similar weights and price points. But having slept in most of those top bags—and after sleeping in Mountain Hardwear’s Phantom 30 on cool nights on backpacking trips from a section of the Arizona Trail in the first days of April and camping at Idaho’s City of Rocks in June to the Canadian Rockies and Wind River Range in August—I place the Phantom 30 among the two or (maybe) three very best ultralight mummy bags for its strategic balance between low weight and excellent warmth. Here’s why.

I slept oblivious to the air temp wearing just underwear and a light T-shirt or a midweight, long-sleeve top on nights in the 40s F/4-8° C on several trips: for three nights in the Wind River Range in mid-August, where we had a lot of wind every night; for a total of four nights on the Skyline Trail in Jasper National Park and the Nigel, Cataract, and Cline Passes Route in the White Goat Wilderness of the Canadian Rockies in early August; while backpacking a section of the Arizona Trail along the Gila River in the first days of April; and camping at Idaho’s City of Rocks National Reserve in June. In the White Goat Wilderness, we had very heavy dew both nights that soaked our tents inside and out, with the condensation inside getting our bag shells wet but not appearing to affect this bag’s warmth or loft at all.

Beyond its status as one of the perhaps five very lightest mummy bags you’ll find in this temperature rating category, the Phantom 30 compares in weight to the lightest and nicest ultralight backpacking quilts.

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The Mountain Hardwear Phantom 30 sleeping bag.
The Mountain Hardwear Phantom 30 sleeping bag.

But I’d argue it’s one of the two or three best ultralight mummy bags for its excellent balance of both low weight and warmth for a bag rated around freezing. That comes down to a key material in Hardwear’s Phantom series bags: the 850-fill down, very nearly the highest fill rating found in sleeping bags (and only six percent less warmth and loft per ounce/gram compared to 900-fill down). That lends the Phantom a top-of-the-charts warmth-to-weight ratio and packability among ultralight sleeping bags.

Also, the bag contains 10 ounces/284 grams of down fill (in the regular), giving the Phantom a fat four inches of loft. That translates to the Phantom 30 weighing a few ounces more than the very lightest bags with this temp rating—but also delivering noticeably more warmth. That means you can push this bag to its temp rating—or lower—without regret (unless you normally sleep cold; see my “Pro Tips for Buying Sleeping Bags” for tips on that.)

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The Mountain Hardwear Phantom 30 sleeping bag.
The Mountain Hardwear Phantom 30 sleeping bag.

That helped keep me warm—even, at times, keeping the bag partly unzipped because I felt too warm—on nights that fell into the temperature range most backpackers will encounter in summer in mid-latitude mountains and in spring and fall in the desert Southwest. As someone who sleeps relatively warm, I’d confidently take this bag out on trips with expected overnight lows around freezing and slightly below (adding some clothing layers as needed).

The adjustable hood‘s face gasket closes evenly and comfortably around my face and head when I want to burrow deeply inside the bag, while the draft collar and tube along the zipper protected me from chilly air outside.The lightweight, anti-snag, two-way zipper has a nice pull tab for grabbing even with light gloves on and never caught on shell fabric.

The Phantom’s dimensions reflect a design priority for minimizing weight and packed volume, measuring 58 ins./147cm at the shoulders and 52 ins./132cm at the hips, and the standard 72 inches/182cm long (regular bag); and while Hardwear does not provide a girth measurement at the foot box, I found there’s plenty of space to move my feet around and stuff a little extra clothing down there to boost insulation and keep that clothing warm for morning.

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The Mountain Hardwear Phantom 30 sleeping bag.
The Mountain Hardwear Phantom 30 sleeping bag.

Overall, at five feet, eight inches and about 150 pounds, I found the regular Phantom 30 certainly efficient in its internal space but also more than roomy enough—for a mummy bag. I believe unisex sizing makes sense in sleeping bags because body shapes and sizes vary greatly within genders as much as between genders. That said, larger or wider people might prefer a bag with more generous dimensions.

The regular Phantom measures just 6×13 ins./15x33cm in its compression stuff sack (2.5 oz./71g), which outweighs standard stuff sacks by perhaps an ounce but delivers added value of $15 to $30 (the cost of buying a compression sack separately) and makes the bag more packable.

The 100 percent recycled, 10-denier ripstop nylon shell with a DWR (durable, water-repellent treatment), among the lightest fabrics used in bags, is adequately durable for normal use with some care.

Mountain Hardwear also offers the Phantom 15 ($540-$580, 2 lbs. 1 oz./941g) and Phantom 0 ($640-$680, 2 lbs. 11 oz./1162g). See my review of the Mountain Hardwear Phantom 0 sleeping bag.

Mountain Hardwear Phantom 30

Warmth for its Weight
Warmth When Wet

The Verdict

For its excellent balance between very low weight and warmth that bests many competitors with the same temp rating, the Mountain Hardwear Phantom 30 has earned its status as one of the very best ultralight mummy bags for backpacking.



You can support my work on this blog, at no cost to you, by clicking any of these affiliate links to purchase a unisex Mountain Hardwear Phantom 30 at, or any other Phantom bag model at

See all reviews of sleeping bags and all reviews of backpacking gear at The Big Outside, and my “Pro Tips for Buying Sleeping Bags” and “10 Pro Tips: Staying Warm in a Sleeping Bag.”

And don’t miss my picks for “The Best Backpacking Gear” of the year.

NOTE: I tested gear for Backpacker Magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See my Gear Reviews page at The Big Outside for categorized menus of all reviews and expert buying tips.

—Michael Lanza

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