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Western Mountaineering MegaLite Sleeping Bag: 30F Down

$470.00 - $500.00

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    • 5ft 6in/Left Zip
    • 5ft 6in/Right Zip
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    • Navy Blue


    28 Reviews


    Not just lite; MegaLite.

    Western Mountaineering gave the MegaLite Sleeping Bag a roomy cut for those who want an ultralight bag without the coffin-like feeling. This down bag features insanely lightweight 850-fill goose down and will lull you to sleep on your warm summer backpacking trips and multi-day bike excursions. The bag's continuous baffle system let you sweep the down to the top or bottom of the bag to suit the night's temps, and the full-length draft tube keeps the chills from sneaking in.
    • Ultra-premium, 850-fill down insulation to retain your body’s warmth and maintain a super-high warmth-to-weight ratio
    • Ultra breathable, packable, high-thread-count ExtremeLite shell fabric encases the insulation without adding unnecessary weight
    • Water-resistant coating protects the down insulation from frost, condensation, and spin drift
    • Continuous baffle system ensures unimpeded loft and and zero cold spots
    • Slightly wider shoulder and waist circumferences ensure a comfortable night sleep
    • Full-length, #5 YKK coil zipper stands up to years of use
    • Western Mountaineering bags are made in the USA
    • Item #WES0042

    Tech Specs

    850+ fill down
    Max User Height
    [short] 5 ft 6 in, [regular] 6 ft, long 6 ft 6 in
    Shoulder Circumference
    [short] 63 in, [regular] 64 in, [long] 65 in
    Hip Circumference
    [short] 56 in, [regular] 55 in, [long] 56 in
    Foot Circumference
    [short] 39 in, [regular] 39 in, [long] 39 in
    Fill Weight
    12 oz
    30 F
    Storage Sack
    Stuff Sack
    Stuff Size
    [short] 6 x 12 in, [regular, long] 7 x 12 in
    Claimed Weight
    [short] 1 lb 7 oz, [regular] 1 lb 8 oz, [long] 1 lb 9 oz
    Recommended Use
    ultralight backpacking, camping
    Manufacturer Warranty

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    Great 3 season bag

    • Familiarity: I've put it through the wringer

    This is phenomenal for a three-season bag for most of the US. With Western Mountaineering using a 20D Microlite XP fabric in all of its ExtremeLite series you know that this bag is going to be super light and durable. 20 Deiner fabric is the perfect blend of lightness and durability, which is why Western uses this fabric. The Microlite XP fabric is a super high thread count making it very water-resistant while remaining in the featherweight category. Along with this Crazy-light fabric Western pairs, this bag with an 850+ fill power down which is RDS approved. In reality, westerns down are the highest on the market, you may see brands that boost a fill power of 900+ which is what westerns truly is. In most tests that Western does with there down it exceeds the test, the reason for the 850+ is because in real-world situations and not in the lab where it's tested it's going to perform as an 850 fill. This bag is well worth the price as are all of Western Mountaineerings bags. If you're in the market for a sleeping bag that's going to perform as well as you and that'll last a lifetime this is the bag. At a mear 1 lb 8 oz, this thing is dumb light and way warm for the weight. If you're a cold sleeper this makes a great summer bag as you'll be toasty down to 30*. if you sleep warm and use a sleeping bag liner you can push this bag well below the 30* mark. Westerns temperature ratings are were a women with long johns and a beanie would sleep comfortably. Although in most cases I'd say they're even warmer than that.

    Pure warmth

    • Familiarity: I've used it several times

    Can't say enough great things about this bag! Unbelievably lightweight, remarkable quality, and warmth you can't beat. I took this bag on a week-long camping trip through Southern Utah... nights can get very cold in the desert, yet I couldn't even tell when I slept in this incredibly warm sleeping bag. This may be rated as a 30 degree bag, but it performed super well for me even when temps dropped below the 30 mark. Made me one happy camper-- and with the quality of Western Mountaineering, you know you'll be a happy camper for a lifetime.

    No Frills Quality

    • Familiarity: I've used it several times

    If you know have even a passing knowledge of sleeping bags, you know that the Western Mountaineering brand speaks for itself. This holds true to their general brand ethos - simple, bomber, and functional.

    This packs down quite small, saving space in your pack for supplies on longer trips or allowing you to carry a smaller pack on a quick overnight. I was able to very comfortably pack everything I needed for an overnight in a 30L pack thanks to this bag's excellent compress ability.

    The best!

    • Familiarity: I've used it several times

    It's true, WM is the best bag maker out there. I've been backpacking all my life and finally got a megalite last winter for this summer in the Sierra. My only regret is waiting so long to get one. The temp rating is conservative IMO. Can go lower, especially if layering up with clothes. Quality and workmanship is unbeatable. Packs up super tiny and lofts up big time when deployed. Perfect for my intentions which are 3 season hiking thru the Sierra.

    None better

    • Familiarity: I've used it several times

    This bag is so awesome. It is best in the 20-50 degree range, but I'm pretty sure with the right clothing on it would go lower. It packs down to nothing and is super light. The zipper doesn't snag and is perfect.

    Amazing bag

      Purely amazing. No matter the climate or the weather I have been in, this bag has me covered. The material is incredibly soft, it's so light you barely feel on the bag on you when sleeping, the zipper has yet to snag, and it's roomy even for a tall guy like myself. It has been worth every penny. After a year and a half this is my go to bag for every trip except in the middle of winter. If I ever need another bag, it will be a Western Mountaineering bag.

      Awesome Summer Bag!!!

      • Familiarity: I've used it several times

      I finally broke down and forked out the cash to buy my first Western Mountaineering bag. I specifically bought this as a summer bag. I am 6'2" 225lbs so I ordered the 6'6" length. Had some technical difficulties trying to order it online so I got a hold of customer service....

      Tangent- Backcountry's customer service is 5 stars!!! They are spectacular. After primarily shopping at another major competitor with 3 letters in its name and having multiple horrible experiences with their customer service department, I decided to use backcountry as my go to store. In no time at all they got my order processed and on its way. I can not speak highly enough about how helpful and professional the rep was... Only wish I remembered his name, but it was not a fluke, ever since then have had the same experience.

      Ok back to the bag,

      Initial impressions-
      Got the bag in and took it out. No packaging issues. Looked the bag and the stitching over. Again no issues and appeared to be done with great attention to detail. Let the littles ones play with the zipper for awhile as they are my best quality control testers. After my 2 year old ran its through the ringers with 0 snags, the zipper still ran smooth. Crawled in side and found that I had plenty of room to move around with out the bag feeling too loose or to restrictive. Plenty of room in the shoulders and the foot box as I turned over and over as if I was on full spin cycle. I am a side sleeper and tend to toss and turn a lot, first test appeared that this bag was accommodating to my sleep style.

      I packed it in to my OR 8L dry compression sack. The bag fit in it and compressed down nicely. Left it in there for a day, took it out the next day, and the loft fluffed itself out in no time, no dead spots observed, the bag seemed to regain its loft quick and evenly.

      First trip was a 3 night trip with night time temps down to low 40's. Slept very warm, 1 night I actually zipped it opened and used it as a quilt with a foot box, which worked quite nicely. Never had any issues with the bottom of the bag over compressing and creating any cold spots. Also did not observe any pieces of down trying to poke themselves out. I was skeptical about the bag material at first, felt like it could rip really easy, but after my initial tests and trips, that fear was quickly put to the wayside. This bag ended up being very tough.

      All in all, I know it is a lot of money to fork out, but it is worth every penny, I am very happy with the quality of this bag and would highly recommend it as a summer/ early fall/ late spring bag!!!!

      "Make a plan, share the plan, stick to the plan"

      Amazing Bag

      • Familiarity: I've used it several times

      I bought this bag last spring when I was working for an outdoor gear store and was able to take advantage of a nice discount. It is honestly my favorite piece of gear that I have ever owned. It's incredibly warm (I would say the 30 degree rating is a conservative estimate), light, packable, durable, and comfortable...and the zipper never snags. The water-resistant outer shell fabric absolutely works...just the other night I was sleeping outside, and a fair bit of condensation formed on the bag, which was repelled brilliantly. Obviously the price tag isn't ideal, but all things considered I think it's worth the price. Also, I'm about 6'1", 170 and the 6ft bag is a perfect fit, IMO.

      Amazing Bag

      What's Not To Love?

      • Familiarity: I've put it through the wringer

      A great sleeping bag for us taller/bigger folks who want a roomier version of your standard mummy bag. This is my second MegaLite bag; the first I "lent" to my girlfriend two years ago when we first went backpacking together and I never got it back. I finally broke down and got another MegaLite so she wouldn't be the only one with a top-end sleeping bag. This bag is so warm that 80% of the time I use it as a quilt and am perfectly comfortable - and I'm not an especially warm sleeper. Compare the loft of this bag to other supposed 30-degree bags and it's obvious the MegaLite has more (better?) down. Great loft in this bag. In my mind it's a high-quality, life-time investment! (FWIW, the girlfriend who borrowed my MegaLite is now my wife and I like to think that me lending her my pride-and-joy all those years ago had something to do with that. ;-)

      Best Sleeping Bag Brand, Period!

      • Familiarity: I've put it through the wringer

      I have owned my Megalite for 10 years. It is the best piece of camping equipment I own. It is incredibly light, packs to the size of a cantaloupe and is even better than advertised from a temperature rating standpoint. This summer I sold mine to a friend and purchase another one right away.

      My Dream Bag

      • Familiarity: I've put it through the wringer

      I loved this thing so much, i ended up getting the kodiak as well for colder trips! I've now had this bag for 5 years though, and I've had no problems at all. I may send it in for some extra stuffing soon, but that's to be expected after close to 6 years of pretty constant use! I didn't really realize how awesome WM is though until I went to shop for a colder weather bag a couple years ago. I actually tried a few other companies over several months (trying to avoid the high WM price tag), but I ended up coming back to this awesome bag company in the end. WM makes a more comfortable bag than other companies with plenty of wiggle room, and they rate their bags' temperatures more conservatively than other companies, which means more warmth! You really can't beat their quality! ...Also, I can zip both bags together with no problems (since one is left, the other right), even though they are different links.

      Perfect choice to fit my needs

        Fwiw, I received my 6' regular Megalite today so, of course, I gave it the once over. . While I didn't inspect it minutely, I saw no noticeable defects in workmanship. The zipper operated smoothly without snags. The material felt nice on the skin. I then tried it on for size. Right now I'm 6'10.5" and 195 lbs with a 42" chest. I wore a base layer with my Golite synthetic vest and Zpacks beanie. I easily fit in the bag at the shoulders and chest with the vest on. I could cross my arms over my chest or leave them lengthwise next to my torso without constriction. The bag also easily fit lengthwise, I had no issues wearing my beanie in the hood, and the draft collar seemed to fit well. In fact it felt like I had about 6" left in the footbox where I could place damp clothing to dry or water bottles without sacrificing foot area. The footbox felt pretty roomy as well without the need to curl my toes. The stuff sack weighed 1.4 oz on my scale. The bag in the sack was 26 oz exactly meaning the bag weighed 24.6 oz. on its own. Admittedly the bag is expensive but I already have confidence it will give me the protection I need while allowing me to manage a lightweight pack. All in all, I know I made the right choice for my needs. Lastly, the purchase supports American workers instead of Chinese. I like that fact a lot.

        customize your down by sending it in.

        • Familiarity: I've put it through the wringer

        this is a high quality sleeping bag if you do buy it and find that you are cold with your 30 degree rating and don't think you are warm enough western mountaineering is a solid company send the bag to them ask them to stuff your bag with a bit of extra down and boost your temp on your bag. i love this bag mainly cause it is so light and with my compression sac i can squeeze this guy in my small light day pack and still have room for the rest of my gear. i bought this cause i was cutting weight from my pack and got all new gear with super light wt in mind. i say get it like i said if it not as warm as you hoped send it in and get a boost of down.

        Loved It

        • Familiarity: I returned this product before using it

        Loved the bag in terms of workmanship and materials, but I returned it when I decided that a 20 degree three season bag and a 40 degree summer bag better fit my needs. I replaced this with a WM Alpinlite and a WM Mitylite.

        WM Megalite wonderbag!

          I have been using my 6' mega for 2 yrs and am so pleased with how the temp rating is right on but I have easily pushed the temp rating by wearing long unders. I have put on my down sweater inside it and been too warm so Im not sure where the bottom temp is on that combo.You can only do that because of the generous cut. Buy this bag and feel like a very smart and patriotic outdoorsperson!

          WM Megalite is for real

          • Familiarity: I've used it once or twice and have initial impressions

          This bag is just great. I am 6'2 185 lbs and bought the long size. I am a side sleeper and prefer space inside of my bag; this bag fits my needs perfectly. Lofty, warm, light, and smooth are the four words that sum up its features. I can't believe a bag this spacious actually fits into the included XS stuff sac. I especially love the smooth inside/outside face material, it just feels very soothing to the touch, unlike the Montbell u.l.'s tissue like material. Few people talked about the function of a smooth face material on a sleeping bag, but the smoothness of the inner surface lends itself to allow easier tumbling and turning, without taking the bag with you.

          My wife and I can even use it unzipped as a comforter, and achieve decent warmth and comfort. It also shows minimum down leakage, which is a serious problem in other bags that I have owned. This is one piece of luxurious equipment that I can honestly say well worth the money.

          Took the bag for an overnight in Zion NP, the low temp. was in the high 30s. With an uninsulated pad, still no problem at all. Even with all the extra space of the long bag, I didn't feel any cold spot the entire night. I do always wear a light insulated hoodie to protect my head and neck. I am comfortable taking this to its rating as is, and to 20s even high 10s with a good puffy jacket and pants (more than enough space for that in this bag).

          Just took the bag for another trip to 10000 ft. alpine snow.

          Low was 29F and windy (inside a single wall tent, good air flow), still good. A little cold when side-sleep, but there's not a fault of this particular bag. Leaning against wife solved the problem. (Is there a side-sleeper's bag?)

          Sweet bag

          • Familiarity: I've used it once or twice and have initial impressions

          This is my first WM bag and I'm hooked. Just took it on a 2 night backpacking trip. Super lightweight & compact. I'm a woman, 5'2 and the 5'6" is perfect. It is roomy in the shoulders good if you move around alot at night and/or for warmer temps but not efficient in temps below 40 (I stuffed my extra clothes in the space to make it work in upper 30's) I do like the bag, but because of the roominess, this will be my warmer weather bag and I'll probably get the Apache for more efficiency in cold wx.

          Simply the best!

            I have purchased 4 WM bags over the years and have steered several friends to them as well. They are simply the best sleeping bags made. Superior quality and performance in every way. They are a work of art. I use the Megalite for most of my backpacking, It's just right for 3 season use.

            Unanswered Question

            Do you know if the Big Agnes Double Z pad would work with this? I’ve had my eye on a WM bag for 5 years and need a sleeping bag now.

            5’6” or 6’0” feedback request.

            Hello everyone,
            I am 5’6” so I’m wondering, when they say max height for the short is 5’6”, would that be head and feet pressed tightly at the ends of the bag, or is the bag larger so someone at 5’6” would still be comfortable?

            Thank you for your feedback, this is my first serious sleeping bag purchase and after reading many reviews I’m going with the, “Buy once, cry once,” ideology as this seems to be one of the best.

            Also, as someone that usually shops REI and has the reassurance of their 1-year warranty, does Backcountry support purchases in any way, should this not be the right fit? (I’m sorry if this is a poor question, I have yet to fully search the website).

            Thank you for all your help!

            Hi Jacob,

            It should still feel comfortable and accommodate you being 5'6". Additionally, all the Western Mountaineering products come with a lifetime warranty. If you have any other questions or need assistance with an existing order or placing an order, please feel free to contact us on Chat or call us at 1-800-409-4502. Thanks!

            Hi, looking at a megalite. My son is getting into Boy Scouts and we will be doing a lot of camping and hiking here in Northern California. Is this the best WM sleeping bag for this activity? Also, I am 5’7” and generally a side sleeper. What size should a get? 5’6” or up to 6’ if I go with the megalite? Many thanks.

            Hey Anthony,

            If you are 5"7 you absolutely need the 6 foot bag. As for if this is the best bag or not, i think a western mountaineering bag is definitely a great choice, but i would be nervous about the temp rating on this bag for certain conditions you might experience in NorCal. From my experience, it can often be colder than 30 degrees in the mountains there... so you may want to consider a lower degree bag (maybe a 15) but totally depends on when the troupes will be outside and where!

            Let me know if I can help more!



            Is there a way to attach it to my sleeping pad?
            At night I always turn around and find myself off the pad

            Best Answer

            Hey Tom,

            Unfortunately this sleeping bag does not have a way to attach a sleeping pad. I would recommend checking out the Therm-a-Rest ProLite 4 Sleeping Pad (CAS003Z). It features a sticky-dot non-slip surface that ensures your mattress stays put for a full night's sleep.

            I need more of a summer sleeping bag used for many activities. I am picking between SummerLite or MegaLite where I like addition of top colar on MegaLite and additional down BUT I am not sure about the size. It is wider than SummerLite.

            How can I know if this will be to big in shoulder area or not. Usually i sleep in base layer.


            What is the circumference of your shoulders? Do you move a lot when you sleep? I mean the Megalite will be more comfortable because you have more room but, you sacrifice a little weight. I'd say if you move around a lot go with the Megalite, if you can sleep still on your back the Summer Lite is a good option.

            Feel free to hit me up at or 801-736-6398.

            Hi, just wondering what the actual length of this bag is in the Long size. I'm just over the height limit at 6'7" and wonder if the length would be too short for me. All other measurements are present except length on their site as well. Thanks

            Hey there, Leta here with Western Mountaineering. Shoot, this is a tough one. You really need a semi rectangular option, and Western Mountaineering does make a bag that I think would work: a 6'6" Alder at 25 degrees. It's semi rectangular, no hood, which is what you would need. The only 7'0" options we have are starting at 15 degrees and colder. The Gear Heads at are awesome about special orders. They will take good care of you!

            Hope this was helpful,


            Sleeping bag liners and pads to recommend. I just got my 6'-6" Megalite and am trying to figure out what liner and pad would work best with this bag? I am a side sleeper! Thanks, Ben

            Hey Ben,

            There are a whole bunch of options. How important is weight to you? What type of R-value are you looking for in the sleeping pad? What type of trips / area will you be taking this set up to.

            Feel free to email directly and I can work with you 1-on-1

            Jared D.

            Expert Gearhead



            Hello Does the megalight open fully into...


            Does the megalight open fully into a blanket like the terralite?

            Or does it zip down one side to the feet, which remain enclosed?

            Many thanks

            Where are the 6 ft west mountaineering...

            Where are the 6 ft west mountaineering bags.every model I look at only has 5-6 and 6-6.

            I need to make one more check before...

            I need to make one more check before investing in two of these Megalite bags.
            Assuming I get a Long LZ and a Reg RZ, can i couple/mate/zip two megalite bags together?

            I have this bag and a longer WM Kodiak, and although the temps of the bags are very different, they zip together without a problem! I've also noticed that a 6ft person can make due pretty well without feeling cramped in the 5'6" bag!

            I wondering about this one or the Highlite....

            I wondering about this one or the Highlite. I'm gonna use it as an ultarlite trekking bag for sleeping indoor or in a tent. For colder conditions I have an MH Phantom 15. Is there any reason to get this one over the Highlite?

            Best Answer

            With the Megalite, you can shift the down around to load up in cold spots and have a bit more circumference, it has a draft collar and full length draft tube, wider cut and a full-zip, but the Highlite is less expensive, narrower, lighter, different material, about the same stuff size, rated 5 degrees higher. Comparing specs side by side, both sound like they would suit you just fine. Nothing that Western Mountaineering makes will disappoint if you appreciate quality and know your needs. That said, my personal preference would be the Megalite, if for no other reason than the extra room.

            Hey guys i know the official packsize is...

            Hey guys i know the official packsize is listed but is that compressed? or just stuffed? ALSO does the bag compress well i want a bag that goes down small =) Cheers!

            this bag comes with a large storage sack, it also comes with an XS 7 X 13 inch regular stuff sack. However, if you want it smaller than that, I recommend the sea to summit event compression dry sack. XS is 6X14 inch non compressed.

            can i order this bag with 2 oz of...

            can i order this bag with 2 oz of overfill?

            This question actually pertains to the WM...

            This question actually pertains to the WM Summerlite, but the answer should be the same for the Megalite, thus I'm asking it here. I was told by a different dealer that a 6' RH zip and a 5'6" LH zip bags "cannot zip together". Does this mean that they physically cannot zip together, or just that there will be a little extra zipper on the longer bag?

            There will just be a little extra zipper... I zip the mega into a WM Kodiak all the time! 1 is 5'6", the other is 6', and the temps are noticeably different depending on the side you end up on (only noticeable on a cold cold night though)... I have also noticed that a 6'2" person can sleep in the 5'6" Mega side without issues though, which is great if one person is warmer blooded than the other.

            Hey, I'm looking at a 30 degree, lightweight...

            Hey, I'm looking at a 30 degree, lightweight bag for summer, late spring and early fall in Idaho. I am having a lot of trouble deciding between the Marmot Hydrogen, MontBell U.L. Super Stretch Hugger #3 and the Western Mountaineering MegaLite. Anyone want to give their two cents to help me decide?

            Hey, I'm looking at a 30 degree, lightweight...
            Best Answer

            Here's my two cents:
            Both Marmot & MontBell make excellent bags. I've used both but when it came to putting my money on the line, Western Mountaineering won hands down for these two main reasons:
            1. WM bags have the greatest warmth to weight ratio. In other words, their ten degree bag weighs the same as the competitions twenty degree bag.
            2. All Western Mountaineering products are made in the USA from the most state-of-the-art materials available.

            I have owned two WM bags for many years & my answer is strictly a personal choice & preference.

            I'm really intrigued by the continuous...

            I'm really intrigued by the continuous baffle construction. Any testimonies to how well people like this? Does the down shift much in the middle of the night? I'm used to opening my bag up to use as a down comforter on warmer nights, and am debating if I want to go with a continuous baffle or divided bag from WM.

            Best Answer

            I agree with Kurt. With a 4" loft bag like this, you don't have to worry much about down shifting (unless you sleep vertically like Batman). Go with the continuous baffle, the sewn through option creates cold spots where the bag is sewn, and is really only necessary when a bag has VERY little down in it (like the WM highlite). This bag has the perfect amount of down for its temp rating and I've never had any problems with down being in the wrong spot.

            Continuous baffle construction is far superior than any sewn through option. Baffles aren't a negative, in fact he baffle gives the sleeper more options. Trust me, down will not move or shift during the night. I'm not even sure it would hinder batman all to much. You can make down shift if you want to, but it takes some significant effort. Sometimes I like to pack a little more on the sides so the top can breath a little bit better. If you just shake your bag a few times with the help of a friend, the down will settle back down evenly again and you're ready to go

            I have one and love it. The advantage of the continuous baffle, is that you can shake the down to one side of the bag, Hint! move the down to the side that you are not going to compress with your body weight. Use a good quality pad (or two) and then you will have all of the down insulation where it will do the most good!