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Western Mountaineering MegaLite Review

The best ultra-premium bag that combines warmth, low weight, good packability, and luxurious comfort
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Western Mountaineering MegaLite Review
Credit: Jessica Haist
Price:  $570 List
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Manufacturer:   Western Mountaineering
By Jack Cramer and Ian McEleney  ⋅  Nov 22, 2023
82
OVERALL
SCORE


RANKED
#1 of 16
  • Warmth - 25% 8.0
  • Weight - 25% 8.0
  • Comfort - 20% 9.0
  • Packed Size - 15% 8.0
  • Features - 15% 8.0

Our Verdict

In the extraordinarily close contest for the best backpacking sleeping bag, the Western Mountaineering MegaLite once again takes home the top spot. Like most of the ultra-premium down bags we tested, it is extremely lightweight and packable, but it's also luxuriously roomy and earned top marks for comfort. Our testers found it warmer than most 30°F bags, giving it an ideal level of insulation for many 3-season applications. The only drawback? The price. Keep in mind that if you can stomach the initial cost and then care for it properly, this bag could maintain its impressive loft for more than a decade. See it ranked against other top products in our article on the best backpacking sleeping bags.
REASONS TO BUY
Spacious dimensions
Super comfortable
Great loft
Lightweight
Made in the USA
REASONS TO AVOID
Expensive
Awkward hood
Good but not great zipper
Editor's Note: This review was read through and updated on November 22, 2023, after a full retest of this sleeping bag alongside some new additions to our lineup.

Compare to Similar Products

 
Awards Editors' Choice Award
Best Overall Backpacking Sleeping Bag
Top Pick Award
Best for Colder 3-Season Conditions
Top Pick Award
Best for Fast and Light Adventures
Best Buy Award
Best Budget Down Sleeping Bag
Best Buy Award
Best Budget Synthetic Sleeping Bag
Price $450.00 at Backcountry
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$384.95 at Backcountry
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$549 List
$549.00 at Feathered Friends
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$100 List
$99.95 at REI
Overall Score Sort Icon
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Bottom Line If we could only have one bag for the rest of our lives, this would be itThe best bag for the coldest shoulder season nightsThe ideal bag when you need the warmth, but ounces matter tooThis inexpensive model has decent warmth for the weight, and features that are well thought outThis bag is comfortable and has decent features - pair this with a bargain price and it's a great deal
Rating Categories Western Mountaineer... Western Mountaineer... Feathered Friends H... Mountain Hardwear B... REI Co-op Trailmade 20
Warmth (25%)
8.0
10.0
8.0
8.5
6.5
Weight (25%)
8.0
7.3
8.4
6.3
4.4
Comfort (20%)
9.0
7.0
6.0
7.0
6.5
Packed Size (15%)
8.0
7.0
8.0
5.0
3.0
Features (15%)
8.0
9.0
9.0
6.5
7.0
Specs Western Mountaineer... Western Mountaineer... Feathered Friends H... Mountain Hardwear B... REI Co-op Trailmade 20
EN Temp Rating (Lower Limit) 21°F 14°F 30°F (not EN rated) 15°F 21°F
Insulation 850+ FP Down 850+ FP Down 950+ FP Down 650 FP Duck Down Synthetic - recycled polyester
Measured Weight 1.5 lbs 1.8 lbs 1.3 lbs 2.3 lbs 3.2 lbs
Compression/Stuff Sack Weight 1.0 oz 1.0 oz 1.0 oz 1.9 oz 1.6 oz
Fill Weight 13.0 oz 17.0 oz 12.0 oz 21.0 oz 34.9 oz
Shell Material 12D Extremelite 12D Extremelite 10D Pertex Endurance 20D ripstop nylon Recycled polyester
Liner Material 12D nylon taffeta 12D nylon taffeta 15D ripstop nylon 30D nylon Polyester
Hydrophobic Down? No No No No N/A
Neck Baffle? No Yes No Yes No
Small Organization Pocket? No No No Yes Yes
DWR Treatment? Yes Yes No No Yes
Zipper Info Full-length / side Full-length / side Full-length / side Full-length / left Full-length / left
Shoulder Girth 64 in 59 in 58 in 62 in 62 in
Hip Girth 56 in 51 in 52 in 53 in 58 in
Foot Girth 39 in 38 in 38 in Not listed 40 in
Compression or Stuff Sack? Stuff sack Stuff sack Stuff sack Stuff sack Stuff sack

Our Analysis and Test Results

Even with competitive recent additions, the MegaLite still rises to the top. It accomplished this with few, if any, changes from its previous versions. Why change what's perfect, right? In all seriousness, the MegaLite now faces stiffer competition than ever. We still love its spacious dimensions, low weight, and cozy warmth. However, if minor issues with the zipper and hood aren't addressed, it could eventually lose its throne.

Performance Comparison


western mountaineering megalite - the megalite is our favorite backpacking sleeping bag because it...
The MegaLite is our favorite backpacking sleeping bag because it performs well in virtually every way and is suitable for almost any outdoor activity.
Credit: Ian Nicholson

Warmth


The MegaLite is filled with down advertised as “850+” fill power. When comparing it with other bags, however, it's important to understand that its fill power is a conservative estimate. Western Mountaineering claims the actual rating of their down is "almost always above 900." They report the lower 850+ number to be on the safe side and indicate the level of loft that's expected once the down is slightly compressed within the fabric of a sleeping bag or garment. In our tests, the 13 ounces of down inside this bag felt every bit as lofty as bags with reported fill power over 900.


Although Western Mountaineering doesn't publish EN numbers on its website, they are on the foot tag of the sleeping bag. The MegaLite has an EN Comfort rating of 32°F and an EN Lower Limit rating of 21°F. This makes it ideal for pushing the boundaries of “summer.”

western mountaineering megalite - though advertised as a 30 f (-1 c) bag, the megalite has a nice...
Though advertised as a 30 F (-1 C) bag, the MegaLite has a nice buffer between that and it's EN limit rating of 21 F (-6 C).
Credit: Ian McEleney

Ultra-premium down bags, like the MegaLite, offer versatility advantages due to their continuous horizontal baffle construction. This means the down insulation is contained within fabric tubes, or baffles, that are perpendicular to the length of the bag. These baffles are called continuous because they're uninterrupted by seams or stitches. This design allows you to move feathers to the top or bottom of the bag, depending on conditions. On cooler nights, shifting feathers to the top will trap additional heat. On warmer nights, you can do the opposite to avoid overheating.

This bag doesn't have a full draft collar found on other models. While this certainly isn't a deal breaker — it helps keep the bag light — backpackers who won't fill out all of the internal space might find it a bit drafty on chillier nights.

western mountaineering megalite - here you can see how the author has moved feathers inside the bag...
Here you can see how the author has moved feathers inside the bag from his left to his right. Doing so lets you adjust the amount of insulation the bag provides for warmer or colder nights.
Credit: Jack Cramer

Weight


The 6'0" size we tested weighed in at an impressive 1.5 pounds on our scale. This places it close to the front of the pack. When you also factor in its considerable warmth, it results in an impressive warmth-to-weight ratio.


The comfortable, wide dimensions, however, do require additional materials. We've tried a few slimmer primo bags that can achieve similar warmth while weighing a few ounces less. The stuff sack Western Mountaineering includes with the MegaLite is light at 1.6 ounces, but there are other sacks that weigh half as much.

western mountaineering megalite - the megalite's 64" shoulder girth is so roomy that it can extend...
The MegaLite's 64" shoulder girth is so roomy that it can extend past the sides of a backpacking sleeping pad. On the occasional open bivy, this may be a minor problem, but it's not really an issue inside a tent.
Credit: Jack Cramer

Comfort


The characteristic that ultimately nudges the MegaLite past its competitors is its comfort. With several extra inches of upper body girth, even our largest testers didn't find this bag constrictive. Our lead tester is slim and a life-long side sleeper. He found plenty of room to roll over inside this sleeping bag. Although this adds a few ounces, the added weight will be worth it for most users, especially when you consider an ultra-premium down bag can maintain its loft and performance for a long, long time. Think about it — ten years from now, might you find yourself appreciating the extra room?


Another subtler aspect of MegaLite comfort that distinguishes it from its closest rivals is the shell fabric. All premium bags feature shells that are soft and weather-resistant. However, we've noticed that some can also be strangely noisy, with at least one tester complaining that the crinkling sound of Pertex Endurance fabric disturbs their sleep. No noise issues were observed with the ExtremeLite fabric found on the MegaLite.

western mountaineering megalite - the velcro tab used to close the hood is kind of awkward to connect...
The velcro tab used to close the hood is kind of awkward to connect and not 100% reliable for keeping the bag closed.
Credit: Jack Cramer

Packed Size


In our tests with an aftermarket compression sack, this bag compacted to a respectable packed volume of 7.2 liters. Although this wasn't the smallest size we saw, it is the smallest for bags that provide a similar level of warmth.


To take advantage of this benefit, however, you will need to purchase a third-party compression sack. The simple drawstring stuff sack that comes with the MegaLite does an OK job at compression but will still leave you with a bag that occupies a couple of extra liters in your backpack. It's also worth mentioning that the included stuff sack is not waterproof. If your travels take you to the rainy Northwest or perhaps paddling in the Boundary Waters, you may want a waterproof storage option.

western mountaineering megalite - the megalite in its stuff sack. if you want to go smaller you'll...
The MegaLite in its stuff sack. If you want to go smaller you'll need an aftermarket compression sack.
Credit: Ian McEleney

Features


All of the Western Mountaineering bags, including the MegaLite, feature a flexible internal strip of plastic along the length of their zippers. This strip gives the fabric next to the zipper critical stiffness, preventing it from snagging. The other thing we like about the zipper on this bag is how far down the side of the bag it runs. This let us open the MegaLite really wide to use as an improvised quilt for two. It also let us have some targeted ventilation on stinky feet. Western Mountaineering zippers could be slightly improved, however, by incorporating anti-snag slides and an internal pull tab.


Another small issue is the hood. It is anchored at the zipper closure with a weak piece of velcro that felt awkward to use. When cinched tight, the hood only provided below-average comfort.

western mountaineering megalite - we love the western mountaineering (top) and feathered friends...
We love the Western Mountaineering (top) and Feathered Friends (bottom) zippers because they snag so rarely. Both could be improved, however, with a pull tab on the inside of the bag.
Credit: Jack Cramer

Should You Buy The Western Mountaineering MegaLite?


The MegaLite is a fantastic sleeping bag, especially for backpackers who are trying to strike a balance between a light pack and sleeping comfort. For dedicated backcountry travelers, the performance benefits of this bag are worth the premium price. In our experience, premium down holds up better to being repeatedly compressed than lower-quality down or synthetic insulation. This means that over the full lifetime of a bag, a MegaLite could ultimately be cheaper per use than some lower-priced bags.

western mountaineering megalite - a round of applause to sulma and mr for making what we think is the...
A round of applause to Sulma and MR for making what we think is the best backpacking sleeping bag!
Credit: Ian McEleney

What Other Backpacking Sleeping Bags Should You Consider?


Readers who like the looks of the Western Mountaineering MegaLite but are more svelte and want to save some weight should consider the Feathered Friends Hummingbird UL 30. It has very similar specs but a narrower cut that works well for slender hikers. If you want to spend more time in the backcountry in the spring and fall, consider the Western Mountaineering UltraLite — it's noticeably warmer.

Jack Cramer and Ian McEleney