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  • Western Mountaineering - Alpinlite Sleeping Bag: 20 Degree Down - Cranberry
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  • Western Mountaineering - Alpinlite Sleeping Bag: 20 Degree Down - Cranberry

Western Mountaineering Alpinlite Sleeping Bag: 20 Degree Down

$540.00 - $570.00

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    • Cranberry

    34 Reviews


    Low weight rules in the big mountains.

    Climbing or traversing technical pitches with a massive load dangling behind you is a bad way to go through life. Western Mountaineering created the Alpinlite 20-Degree Down Sleeping Bag for alpine climbers and weight-obsessed backpackers who demand top-shelf quality and bottom-line weight savings. Its 850-fill down insulation boasts some of the highest quality loft-to-weight ratio around, meaning it's surprisingly warm for how little it weighs. Western Mountaineering wrapped this insulation around a highly breathable shell to keep the down light and lofty when you're sleeping in a tent under a rainstorm.

    • Ultralight sleeping bag designed for alpinists and backpackers
    • Breathable shell fabric keeps down lofty
    • 850-fill down provides a high warmth-to-weight ratio
    • Continuous baffles and a down-filled collar prevent cold drafts
    • Wider shoulder girth allows for extra layering in cold environments
    • Western Mountaineering bags are made in the USA
    • Item #WES0041

    Tech Specs

    850-fill down
    full-length YKK #5
    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
    [short] 17 oz, [regular] 19 oz, [long] 21 oz
    20 F
    Storage Sack
    Stuff Sack
    Claimed Weight
    [short] 1 lb 13 oz, [regular] 1 lb 15 oz, [long] 2 lb 1 oz
    Recommended Use
    backpacking, alpine
    Manufacturer Warranty

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    This is a great bag!

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

    I’m 5”11 185 lbs with broad shoulders and the 6 foots fits me perfect. I had plenty of room even wearing a down jacket. I used it on a portaledge with a bivy and it kept me pretty warm despite the 20 degree weather and wind. Had a hard time crawling out in the morning it was so comfortable. I’m excited to take this bag out for more adventures.

    Great work WM, this bag is spot on!

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

    As age and injury have crept up on me, so has the challenge of adapting to my outside endeavors. Out of five of the 15-20 degree bags I have owned over the last 25+ years the Alpinlilte sits at the top of the list.

    I was able to test this bag on a recent bikepacking S24O in the Manti LaSal mountains of Central Utah. At 8000+ feet the temps got down into the low-mid 30's.

    I'm 6'1" 190lbs with fairly broad shoulders; the 6' size fits me comfortably while still maintaining its efficiency. My morning socks, glove liners and a small electronics ditty bag had enough room to stay out of the way while I slept. The plush foot box maintained warmth better than any of my past bags and left me confident this bag will outperform any of my older bags down into the 20's.

    I'm looking forward to putting it to work on a fishing trip in the near future.

    Great work WM, this bag is spot on!


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

    I've been eyeing this bag for a number of years now and finally pulled the trigger. I'm way happy I did so, too. Super lightweight and packable. Really warm for how light it is too. I only tried out on a colder night inside, so nowhere near the 30 degree low temp rating. I am excited to put it to the test in some higher alpine camps later this summer. This one is a little bigger and heavier than the UltraLite. I do not mind the extra couple ounces to get the shoulder room.

    Perfect 3 Season Bag

    • Familiarity: I've put it through the wringer

    I have been using Western Mountaineering bags for years and can confirm that they are unmatched in regards to quality and performance. When you buy a "made in the USA" WM bag, you are investing in a bag that will keep performing year after year. In fact, if the bag ever starts to lose it's loft, WM will re-stuff the bag for a nominal fee.
    The Alpinlite really fits the bill if you are looking for One 3 season "comfort" option. I say comfort, as WM also offers the Ultralite, which is the same but more narrow(59 in shoulder circumference vs 64 in at a 2oz weight savings and a slightly lower fill weight). It legitimately will sleep comfortably at 20 degrees and regulates temp. extremely well thanks to a breathable shell and continuous baffling. The weight and ability to compress make it an ideal choice for thru-hikes, bike packing, alpine climbing, or any other activity where weight is a premium and performance is mandatory.

    Unmatched Construction

    • Familiarity: I've put it through the wringer

    WM products are made with some serious quality. Everything I own form them is well above similar products Ive used from their competitors. This is my go to backpacking bag. It fits in a small compression sack and takes up very little space in my pack. Ive got nothing bad to say about it. No cold spots, great zippers, and excellent stitching. The flat spots near the zippers are a great touch to keep them from getting hung up on material as well. I've used this thing a ton and it still looks great and appears it will last forever.

    The sleeping bag version of a Lexus!!!!

    • Familiarity: I've used it several times

    I'm training and preparing to do the A.T. next year and so I've put a lot of time and research into gear- including sleeping bags. I bought one last year that was synthetic fill, but weighed more than it should have for being $180 +. I struggled with justifying the purchase of a $600 sleeping bag, but I tried to remember that if I did not sleep well, my performance and chance to succeed on the A.T. would decrease. I paid the money for this sleeping bag with great trepidation. However, I LOVE this sleeping bag. Legit- I slept on my living room floor the day I got it (over achiever I know). It is very comfortable, and VERY well made. It compacts small and weighs next to nothing. I'm very pleased with this sleeping bag. I've taken it on two overnight trips so far (temp around 15-20 degrees) and this bag kept me plenty warm. I think this is the best purchase I've made on my gear thus far. I'm taking it on a few more trips this month but I'm sure it'll perform just fine.

    Anyone looking for a HIGH quality sleeping bag, you can't beat this. This is as close to a Lexus as I'll ever get. I love this sleeping bag.

    Awesome bag!

      Western mountaineering bags are extremely well built and you get what you pay for. I use this bag in all weather and can regulate my body heat perfectly. I had mine over stuffed which I contemplate if it was necessary but love it all the same. Loft, warmth, light weight and never snag zipper is just about all I can ask for in a sleeping bag.

      Amazing first impression

        I picked this bag up after lots of research, looking for the right bag for me that would have the most longevity. I settled on the Alpinlite for its comfort and versatility. I took this out over the weekend into the Olympic National Forest. It didn't get too cold so I can't talk much about warmth, but I'll say it was extremely comfortable and had plenty of room. I was able to roll around onto my side and belly without being constructed or binding up the bag. I'm 6'1 170lbs and got the 6'6" model.


        • Familiarity: I've used it several times

        This is an amazing sleeping bag. This bag is so lightweight it is great for backpacking trips. I have used it several times on camping and backpacking trips and am very happy. It is so small and easy to carry. This bag is also very warm. I tend to get very cold but am roasting in this bag. Great purchase!

        Maya, this is such a great bag. The shape, the temp rating - all good. And made in the US of A!! Even better. If anyone wants a hand made, amazingly crafted sleeping bag, then buy a Western.

        Thanks for taking the time to write,

        Western Mountaineering Rep

        Might Ruin Your Climbing Trip

        • Familiarity: I've used it several times

        When Western says they only make quality products they are not lying. After 6 years of owning another down bag which was -20, I sold it an splurged on this one. How do you go from -20 to 20 and still intend to do mostly the same activities? Let me try to explain.

        People tend to get hung up on the temperature ratings and this can create a lot of confusion. Instead I try to focus on the amount of down used, the quality, and how much room is in the bag. With Western its fairly easy because they only use good 850+ down. From there I look at competitors. Top quality competitors are using around the same amount of down to achieve this "20 degree" rating, 19 0z of down fill, some even get lower then 20 degrees with same amount of down fill.

        More room = more comfort which also means its harder to heat and keep the heat in that dead space. I am a wider person by nature and therefore I needed this bag versus the other 20 degree bag from Western called the Ultralite. So the Ultra Lite has less room (shoulder circumference of 59" versus 64" with the Alpinlite) which means its easier to heat up but, not comfortable for someone my size 5'8" 200 lbs.

        So around 19 oz of fill and a shoulder circumference of around 64" at 6' long because I need to be able to dry out extra clothes at night inside the bag, and or boot liners. This formula puts me in a comfortable bag that I can roll around in and within the temperature range I really want to use it in which is 0-40 degrees Fahrenheit.

        Now which bag weighs the least and packs the most? On any camping trip where the tarp and sleeping bag are being used weight is instantly an issue. Add climbing ropes or skis and my poor little 35 L climbing/ski pack is crying at the site of my gear splay which I fully intend to stuff inside that bag. Look at a few other competitors out there in the same temperature rating, fill weight, and price point. Its almost impossible to find one that has the same shoulder circumference, can use only 19oz of down, and keep the weight under 2lbs. This is why Western bags cost a little more and in my opinion are the best out there.

        So how do I plan to use it on 0 degree nights? By various layers and sleeping pads.
        1. If its 0 degrees you have an insulated jacket and a fleece most likely. Wear that inside the sleeping bag and instantly its warmer in there. If it is a big belay parka then I would drape that over the bag as opposed to going inside as it will compress the down in the jacket and bag losing loft. Why waste all that weight to only use those layers on the climb or hike? Boot liners also great to toss in there. Sure you lose some of the comfort promised but, you get to use a lighter 20 degree bag in 0 degree temps.
        2. Sleeping pads MATTER! On warmer nights I only roll with my Z-Lite foam pad, colder nights in the snow I use the NeoAir XTherm air pad and on really cold night, I use both.

        I will say take this review with a grain of salt as temperatures and what is comfortable or acceptable is different for everyone. If it gets really cold, I might have a cold night which would suck but, its worth it to me to find that perfect balance and push the limits of the bag. Because it compresses so small and is so light, the chances of a successful climb go way up. With a smaller compressed bag, I can still use my lightweight climbing pack which means I dont need to carry two packs, a summit pack and the 60 L to carry everything to high camp. It being light matters a lot in regards to how my legs feel the next day. To push these limits of temperature ratings and what I can get out of 19oz of down I feel you can only use the best which is Western.

        Picture is taken from CMC Camp with Grand Teton in the back round. The West is on fire and it produced a bunch of haze obscuring much of the landscape.

        If you have anymore questions feel free to send me an email or call!

        Bill Porreca

        Might Ruin Your Climbing Trip

        Might Ruin Your Climbing Trip

        • Familiarity: I've used it several times

        Part 2! Site wouldnt let me finish my essay in one review!

        Side notes about the company. Bags are made in the USA! They will re-stuff the bag full of down after years of use for a nominal fee. They will also over stuff bags to boost the warmth rating, and can be specific about where that extra down goes, like in a foot box . The re-stuffing of the bag after 20 years of use sold it for me, its not a heavy price tag at that point, its an investment into years of successful climbs and skis descents.

        Definitely invest in a dry compression sack. My favorite is at 6' it requires a Small size. Another option is which Is what I used in the picture, 8L. The ODR ones are tough to stuff though as the opening is really small compared to the Sea to Summit.

        The bag comes with a stuff sack (not compression) and a storage bag. Dont keep the bag stuffed while at home, use the storage sack it comes with, keeps loft of the down longer.

        So how will it ruin your climbing trip? Woke up at 3am for an alpine start, couldnt bring myself to get out of the bag. The bag was just too comfortable, even on just a foam pad. Told my climbing partner that I was going to lay down real quick after my bowl of oatmeal and fell asleep for another 2 hours. I was in charge of the alarm.

        If you have anymore questions feel free to send me an email or call!

        Bill Porreca

        Might Ruin Your Climbing Trip

        Best sleeping bag

        • Familiarity: I've used it several times

        This sleeping bag is perfect. With a stuff sack this things packs down really small. Weighs close to nothing and is super comfortable. On this last trip all of my friends wanted to check this thing out. Every time I went back into my tent I caught my wife inside my sleeping bag instead of hers. Looks like I'm going to have to buy her one too!

        Best sleeping bag

        Boyfriend loves it!

        • Familiarity: I gave it as a gift but have feedback to share

        I bought this bag for my boyfriend, Logan, for his birthday this year. He just got back from a climbing trip in Alaska and said this is the best bag that he's ever owned. He and his friends camped on the Pika Glacier for about a week where he slept in the Alpinlite on the glacier, in a tent on a bivy ledge, and next to a river on the hike out. He was super stoked to be able to pack it with him to take up on a climb in order to bivy on a ledge. One of his friends brought up a half bag and a down jacket for the bivy because he couldn't fit a full sleeping bag with his climbing gear. Logan was able to pack down the Alpinlite enough to fit it into his climbing pack and it kept him warm the whole night :) This is the perfect bag for any climber that is concerned about weight but still wants to be warm!

        Logan is 6'4" and the 6'6" bag is perfect giving him just enough extra space in the foot region. I chose this bag over the WM Ultralite because Logan has broad shoulders and likes to move around in his sleep.

        Boyfriend loves it!

        Hey Mallory - Leta with Western Mountaineering here... Thanks for the great review. I couldnt agree more. Western bags are the best, and even though I rep the product, I am pretty picky about the company I keep and can't see myself selling anything that I don't fully believe in. That's what makes this brand such a pleasure. The besy bags made AND in the USA!!! BOOM!

        Great picture! Keep up the adventures!


        I am just spreading the good news:

        • Familiarity: I gave it as a gift but have feedback to share

        "Having spent 3 months living outdoors, I could not of stayed sane without this bag. It instantly produces warmth and traps in body heat all night, while its breathable fabric wicks out your sweat. The extra lofty feathers makes your outdoor campsite feel like you are sleeping within a cloud. The bottom foot box provides just the right size to help trap in heat where the shoulders has extra room to move around and stretch out. I'm 5'4" and believe it or not went with the 6' bag and really enjoy the extra space. The best part of all is this bag tucks down into a small and super light travel sack.

        The extra money I would normally not be interested in spending was well worth the investment, and will provide me years of great sleep outdoors."

        Eric Watford

        Expert Gearhead


        Instagram: @ericwatford

        2000+ Miles and still fantastic!

        • Familiarity: I've put it through the wringer

        I used this bag on my thru-hike of the Pacific Crest Trail. If that's your intent, this bag will be amazing! If not, just know that after 5 months of consistent use, I am still 100% Satisfied.

        The PCT is like one giant gear review, not just for your own gear, but you get to see how other's work as well. I believe that this bag is not just survivable to 20 degrees, but COMFORTABLE. I had many friends with other bags, some lighter, some not, but most of the bags with equal ratings, just didn't stand up to this one. Forget the mainstream brands, WM temp rates their bags with accuracy and integrity. Everyone I met with a WM bag, loved it!

        Not only was I always warm, I didn't wear much of anything inside it for extra warmth. I only set up a tent on nights with chance of rain or too many mosquitoes. Through the cold of desert nights, the high sierra, winds like you wouldn't believe, and the North cascades in the fall, it was easy sleeping. I used a Z-lite pad the whole time.

        I've cowboy camped in windstorms strong enough to make a tent useless and this bag keeps the wind out, frozen water bottles on Mt. Whitney with windchill enough to make everything hurt, this bag warmed me up. Condensation frozen on it like an M&M candy coating, still warm.

        The black inside is also nice. If you get this bag wet and have more days to spend in it, the black really helps dry it out in a sunny spot.

        Sometimes, it was just too warm for this bag, but it works well as a quilt in those circumstances.

        After so many nights hiking, dirty, sweaty, day after day, any bag is bound to get dirty. Yes, it will lose some loft to your body oils and dirt. However, down wash and the instructions on the WM website and it is as good as new with no stench.

        Sure, this bag costs a pretty penny, but if your sleep is important to you, you can't go wrong here. This bag combines light weight, fantastic warmth, and outstanding american made workmanship, to create a seriously great 3-season bag!

        No more cold spots!

        • Familiarity: I've put it through the wringer

        I had a zero degree bag that was too bulky for my backpacking needs, and it had cold spots in the synthetic filling. No more! This bag is incredibly light (I got the long and it's just a couple ounces over two pounds in stuff sack), very small and very warm. I'm perfectly comfortable in 20 degree weather, and although I don't have much occasion to be out in temps colder than that, I'm sure that it would be sufficient with some thermals on in the bag. Expensive, yes, but worth all the money!

        Ridiculously light, absurdly warm

        • Familiarity: I've put it through the wringer

        I use this as an Aussie winter bag, which I guess is '3-season' for northern hemisphere people. Whenever I take an old bag to save wear on this good one I miss it. Loft has lasted very well, but I do store it carefully.

        first and last down bag

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

        I purchased this bag for myself as I have gotten into backpacking, and was tired of carrying my overweight and oversized kelty synthetic bag. This sleeping bag is just awesome!!! So warm I end up hanging a leg or arm out in 30*f weather! This bag is light, super small when packed, and one of the truest temperature ratings I've ever encountered. you will not be disappointed with this bag even down to the 10-15*f range.

        Sweet bag!

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

        I'm 6'1" 225 and this is the perfect bag. I considered an Ultralite 20 but VERY happy I went with this instead. I need the room to turn & like the option to keep other clothing inside for something warm to wear in the morning.

        I used it inside a double walled tent with a Thermarest Z-Lite SOL Sleeping Pad underneath. I wear merino wool socks inside mine along with "whatever" choice of long underwear as it was in the 20's where I lived. I was in my backyard & just wanted to test everything out. I also wore a 80% polyester/20% nylon blend balaclava; Cordura from Ranger Joes (that I noticed was surprisingly better than the merino wool offering from Smartwool)

        Staying warm was not a problem in this bag, and I did not cinch up the available ties (there was no need as I had on a balaclava) No cold spots, even when my heels came off the mat & were in direct contact with the freezing tent floor I'd barely notice it, but I did have to scoot back up on the mat where I belonged. I can't tell you from experience (as it is very rare to get into the teens here temp wise) but I have a confidence I could have done so, but I bought the bag for a 20 degree rating only because that's the worst it gets around here & even then its only for a few days max.

        The only gripe I had about my night was traffic noise on the adjacent highway I was not used to hearing from inside the house

        How small does the large pack down to?

        What is the weight for this sleeping bag?...

        What is the weight for this sleeping bag? The weight is listed on the Western Mountaineering website as 1 lb 15 oz for the regular, not 1 lb 3 oz as shown here.

        Unanswered Question

        From OutdoorGearLab: "Some of the smallest...

        From OutdoorGearLab:

        "Some of the smallest premium companies, such as Western Mountaineering, source the highest down from geese that aren't live-plucked or force fed; they collect naturally shed down from molting. Some vegans might consider avoiding down down products or purchase them from a company such as Western Mountaineering, that guarantee no harm to animals."

        Can anyone confirm this? I didn't find anything about it on

        I am trying to decide between the Alpinlite...

        I am trying to decide between the Alpinlite and Ultralite. I am a side sleeper and toss and turn throughout the night. Avg build guy at 5'9" 160 lbs. Which would you recommend?

        Do you prefer a little more room for tossing and turning inside the bag or for the bag to move with you as you toss and turn? If you prefer inside the bag, go Alpinlite. If you want the bag to toss and turn with you, Ultralite.

        You'll fit fine in both, but the Ultralite is a true mummy bag and the Alpinlite will be a little more roomy but have more internal "dead" space to heat up--so it'll have more down and more fabric and be an ounce or two heavier...

        Thanks for the quick responses. I normally am a warm sleeper so the empty space is okay. I prefer to have the room when I do toss and turn. The true mummy would be a little to compact I guess. Thanks looks like I will go with the alpinlite.

        If im going to buy an waterproof compression...

        If im going to buy an waterproof compression sack as well, how many liters should i get it in?

        Yeah, O4F hit that right. In say something like the Sea to Summit eVent Dry Sack, I would definitely go with the Small size (10-3.3L). Rule of thumb with comp sacks and sleeping bags- start with the original stuff size, let the straps do the work and compressing for you. Hope that added to the conversation.

        The weight on this bag is incorrect, that...

        The weight on this bag is incorrect, that must be the fill weight.

        I am 6' exactly, should I go with the long...

        I am 6' exactly, should I go with the long or would the Reg. be ok?

        Best Answer

        Hey Spencer,

        I'm 6'-0" and own an Alpinlite. You can pull off a regular, but I prefer the 6'-6" model. I tried both sizes out before I bought, and the reg left me feeling short of shoved into the hood and right there with the draft collar. I longer one also gives me the ability to hunker in a little more and to shove some clothes down in the footbox. This is a great bag!!

        ...And for everyone's consideration that has ever measured their height and used that number to determine which bag length is for them- remember that when you measure your height, your foot and ankle are at a right angle. When you sleep on your back, your feet naturally relax into a position of plantarflexion (downward). This can add at least a few inches or more to the amount of length you need.

        you guys have the weight listed incorrectly...

        you guys have the weight listed incorrectly for this bag. It looks like you have the FILL WEIGHT listed as TOTAL WEIGHT.