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REI Sub Kilo 20 Down Sleeping Bag (20 Deg)

Availability: Out of stock.


I’ve owned my REI Sub Kilo 20 down sleeping bag for about 2 years. It’s a pretty utilitarian mummy sleeping bag that provides good value at a good price ($239). Like all down bags, it  compresses down very well and takes up little room in your pack. It is also fairly lightweight weighing 28.7 oz. The Sub Kilo 20 contains 750 goose down fill and has a comfortable polyester tafetta lining. The outer shell is ripstop nylon. The bag also has a full length zipper, but I’ve found that this snags fairly easily and you need to be careful with it.

However, in my experience the Kilo’s temperature rating is over-rated. This is not a 20 degree bag. Personally, I think that rating is probably closer to 30 degrees provided you have a thick sleeping pad underneath you. I have spent many a cold night in this bag and would not recommend it to someone who is looking to make an investment for serious 3-season backpacking use. It is fine for use in high summer but if you plan on camping in early spring or late fall, get yourself a better bag. I’d recommend checking out a Western Mountaineering Ultralite 20 bag which has 850 fill goose down and is amazingly warm. It’s a bit more expensive, but I expect mine to last for many years to come. review

A trusty 20-degree bag with few frills—except for solid construction, light weight, and packability.

Why It's Cool: Cuddling up to the two-pound-two-ounce Sub Kilo definitely took the edge off a few damp, chilly nights in the Green Mountains of Vermont. Two curvy lines stitched down the length of the bag to prevent the 700-fill goose down from clumping worked as billed: No cold spots arose in the wee hours. » The neck drawcord is flat, and the one on the hood is round—so you can tell them apart in the dark when you grab the clip they both run through to cinch 'em tight. » In its stuffsack, the Sub Kilo easily cinches down to the size of a volleyball.

Hmmm . . . The Pertex nylon shell isn't weatherproof, so don't ruffle your feathers by exposing it to a downpour. Review by Rebecca Mezoff (October 25, 2006)

I have used this sleeping bag extensively on weekend trips, week long trips, and my 500-mile Colorado Trail trek. The Colorado Trail hike was 45 nights and a conservative estimate of total nights in this sleeping bag both backpacking and car camping would be 100. Most of my backpacking has been done in Colorado, Nevada, and California and I have not experienced sequential days of rain or snow while using this sleeping bag so can’t comment on its performance when damp. I started my Colorado Trail hike with an old sleeping bag which did not keep me warm, and within a week I ordered this bag from REI and had it sent to my next mail drop. REI was great about this and had no qualms about sending the bag general delivery. I had suspected I would need a warmer bag and had researched and picked this one before hitting the trail.

I am a cold sleeper and I always wear some kind of long-underwear and thick socks to sleep in. I also always wear a fleece hat and will put on my thick fleece jacket if the temperatures outside get below about 45 degrees F (7.2 C). Unless it is very cold outside, I do not use the hood feature of this sleeping bag. I don’t like to have anything cinched around my head because I flip flop all night long and the back of the hood ends up over my face. I have used the hood feature on very cold nights and found that it did keep me warmer although I had to keep shifting the bag to keep my airway clear.

I use a 2/3 length RidgeRest pad most of the time when backpacking. I find often when it gets below 45 degrees F (7.2 C) my feet and legs get cold and I curl them up onto the pad. Because my thighs are so long, there is not enough room inside the bag to bring my knees all the way to my chest, so the whole bag gets pulled up with my knees. Because I turn a lot in the night, the bag often ends up with the bottom on top of me. Since the Sub Kilo has even insulation all the way around instead of less on the bottom as some sleeping bags do, the bag turning in the night has not been a problem for me unless it is cold enough that I need to use the hood feature. Generally I put my pack under my head with any unused clothing and use my thick fleece for a pillow on top of the hood portion of the bag. By morning invariably the bag has migrated somewhere and the hood is on top of my head or behind me, but this doesn’t seem to stop me from sleeping well. I do occasionally carry a lightweight short Therm-a-Rest pad and have similar results with that pad and sleeping bag combination.

The Sub Kilo kept me warm at 12,000+ feet (3650 m) elevations camping under the stars mid-summer on the Colorado Trail in 2003. Temperatures for these nights were around 30 degrees F (-1 C) which is the coldest I have experienced with this bag. On at least 10 occasions backpacking in Colorado, I have waked up with frost on the outside of the bag around my head, but was warm inside (these were occasions when I was sleeping without a shelter).

I used this sleeping bag in the Wind River Range in August of 2006 and found that in similar conditions it was no longer keeping me warm (the bag is now 3 years old). This year I was camped for 5 nights at elevations between 10,000 and 11,000 feet (3048 and 3353 m) with temperatures no lower than 40 degrees F (4.4 C) and although I was not shivering, I found myself trying to get my dog to curl up next to me several times each night to keep me warm. I suspect the inability of the bag to keep me warm this summer was due to its age and heavy use as well as my (unfortunately unintentional) loss of weight over the last couple years.

I take care to dry my bag out before stuffing or take it out to dry during the day. In very warm weather I leave it unzipped and drape it over me like a quilt. This works well.

I have used this bag on numerous car camping trips also. Generally for summer camping when I will have a full length pad and a double wall tent, I leave the bag unzipped and drape it over me. My car camping trips are infrequent and are generally in warmer places than where I would be sleeping when backpacking.

I made a tarp with netting attached to the edges which I use for a shelter (this is similar to a Henry Shires TarpTent of the original design). My tarp tent tends to collect a lot of condensation, especially when I’m hiking with my dog, so the outside of the bag often gets damp during the night from brushing against the tarp wall. This kind of moisture does not seem to seep into the bag to any great extent and after 30 minutes in the sun it will be completely dry.

I currently use a Mountainsmith Ghost pack which is a small internal frame pack with hipbelt. The Sub Kilo fits nicely into the bottom of this pack in its stuff sack. I like the ease with which you can grab the sack from the bottom of the pack with the straps on the compression sack. However, if I had a bigger capacity pack, I would probably sew a lighter weight waterproof stuff sack for this sleeping bag as I feel that 2.1 oz (60 g) for a stuff sack that isn’t even waterproof is a little heavy.

Long term results: I have been using this sleeping bag for three years now and am still pleased with it considering how much use it has given me. REI now has a women’s version of this sleeping bag and if I were to choose now, I would get that version. The regular bag I am using is too roomy for my skinny frame and when it gets really cold, I have to tuck the bag around me to take up some of the air pockets. In the last year I have had much more difficulty staying warm at high elevations and have purchased a -5 degree F (-20 C) bag for high-altitude hikes. The nylon on the Sub Kilo has remained in good shape and does not stain easily. The zipper does catch the shell with some frequency which can be annoying if you’re trying to get out in the middle of the night. There is nothing worse than when my dog is trying to get out of the tent at 2 am to chase a racoon and I find myself stuck in my sleeping bag! Well maybe it would be worse if I had to pee as well.

This is a good basic lightweight sleeping bag which has served me well for the past three years. It was a good investment.

Things I like:
1. warmth to weight ratio is good
2. the bag still feels cushy and cozy after much use and no washings
3. it stuffs to a very small size
Things I don’t like:
1. after three years of moderate use, the bag seems to have lost some loft and does not keep me as warm as it used to
2. I am quite thin and the bag is roomier than I’d like in the torso which means I often end up tucking it around me to decrease air pockets
3. Even when new, it never kept me warm down to the rated 20 degrees F (-6.7 C)


User reviews:

Greg, 0/0/00 User Rating:
"I have to admit I didn't consider myself "down folk" until I tried this extremely lightweight (2 lbs. 4 oz.) 700 fill-power down bag. I've yet to fully test the 20 degree rating, but have found it very lofty, warm, and comfortable thus far. The bag is very well made, and the pertex nylon shell and microfiber lining help keep moisture under control. I wasn't really looking to pay $219 for a bag, but I couldn't be more pleased with the investment."

bob, 0/0/00 User Rating:
"I was always a synthetic person with the big compression sacks and never really considering down for two reasons 1.To vurnerable to water 2. To pricy for warmer bags. Well this bag proved me wrong(still put a dent in my wallet $200) but its water resistance is great i accidently spilled my nalgene on it and i just brushed it off and the shell wasn't even damp!overall this was a great value plus the space you wil save"

Brian, 0/0/00 User Rating:
"This is the best bag I have ever owned. It packs down to the size of a football, and it's so light, I barely know it's in my pack. I have no problem sleeping in 25 degree weather with this bag. The excellent draft tube keeps out breezes through the zipper and neck area, and the mummy effect works wonderfully when the hood is cinched. A+++"

Bill, 0/0/00 User Rating:
"A very good, lightweight bag. Some have said the temp rating is optimistic, but I recently slept in 20 temps, wearing what I would normally take along anticipating subfreezing temps,(long underwear, balaclava, fleece hat) and was fine. Quality seems to be fine, a couple of years use, very very few loose feathers. Perhaps the big names, Western Mountaineering or Feathered Friends, would be even loftier, and a few ounces lighter, but this is a very solid bag at about $100 less than those. I will say it is not generously cut at the shoulders, I am not big at 6 feet and 160 lbs., it is a bit close and does not allow for layering in very cold weather. Also the tubes seem rather loosely stuffed, if you have had it stuffed tightly it takes a lot of fluffing to get it puffy again."

Jeff, 0/0/00 User Rating:
"Great deal! I weighed mine on a digital scale and it's less than 2 lbs. Regular size is OK for me (6'0", 170 lbs.). I love the full length zipper. If it's warm I unzip the bag and use it like a blanket. I want to replace the compression stuff sack (3.5 oz.) with a lighter sil nylon non compression sack. Also, gotta love REI's return policy."

Pete, 0/0/00 User Rating:
"I purchased this bag for a winter camping trip up to Humboldt County over this past New year's in 04'. Overall, the stuff size was great, the weight was very good, and the bag was very comfortable. The only downisde that I felt was that it isn't a 20F bag, and more 25F to 30F. I was still cold on the river bank we slept on for two nights and i had a ThermaRest pad, a North Face VE-25 tent with rainfly on, and don't think the temp got below 30F. I recommend this bag as it is nice and a good value, but i wouldn't trust it as a 20F."

Woody, 0/0/00 User Rating:
"This review is as much a review of REI and their willingness to stand behind their produts. i owned an REI Plar Pod sleeping bag for two years.It was rated 30 degrees. I froze, with sleeping clothes and liner at 40 degrees on more than one occasion and REI replaced that synthetic bag with this Sub Kilo. I paid a nominal difference and am forever sold on where I purchase outdoor items. The sub kilo has performed well, is a bit optimistic as a 20 degree bag, but then again I live in Florida and barely experience temps below 30 degrees. packs small, 2.2 lbs (even tall model) and water resistance is good, High value bag."

Jimmerpohl, 0/0/00 User Rating:
"I had exactly the same experience as "WOODY" and live in Florida as well. The difference is it happened in 2000. REI was super, the Sub Kilo long is my favorite 20 degree bag and I am forever sold on doing business with those folks in Seattle."

Rich, 0/0/00 User Rating:
"This bag is extremely lightweight and compresses smaller than any other sleeping bag I've seen. Sounds great, right? Unfortunately, its poor loft makes up for its benefits. At best, I'd consider this a +32 degree bag. Great for summer camping, but that's about it."

ed, 0/0/00 User Rating:
"I had this bag for about three years now. It is very light and compact leaving you pack with lots of space. My only complaint is that I get cold when the outside temperature gets below 5C (40F). I also wish it had a draft collar and maybe a small pocket I can put a watch or earplugs (for when you are in a communal hut)."

thomas, 0/0/00 User Rating:
"I've got a circa 2002 model, which I bought during an after-christmas markdown for $183. It's been surprisingly dependable, although I do take very good care of my equipment. i use a more generous stuff sack than it came with. down leakage has been moderate. i would also say this bag is not a 20-degree bag."

King Fish, 0/0/00 User Rating:
"I have used this bag in almost all conditions. Small and light weight. Comfortable at 40 degrees with light weight long underwear, and hat. At 30 degrees fleece pants and shirt, thick wool socks, and fleece hat. i would not go any colder than that. Get another bag."


  • Light weight, and packability, warmth to weight ratio, comfortable
  • The Pertex nylon shell isn't weatherproof, so don't ruffle your feathers by exposing it to a downpour.
  • $159.00
  • 3 Season Camping, Backpacking
  • 0.0 kg / 2 lbs. 4 oz.
  • Tech Specs:

    • Temperature rating (F)    20 degrees Fahrenheit
    • Average weight    29 ounces
    • Shell    Ripstop polyester
    • Fill    750-fill goose down
    • Lining    Polyester taffeta
    • Fits up to    6 feet
    • Shoulder girth    57 inches
    • Hip girth    53 inches
    • Stuff sack size    7.5 x 15 inches
    • Sleeping bag shape    Mummy
    • Gender    Unisex 
    • Vertical Baffle construction allows the goose down to remain fully lofted and keeps it from shifting and migrating, preventing cold spots
    • Contoured hood, roomy footbox, full-length locking zipper, full-length draft tube and muffler all keep body heat in and cold air out
    • Internal pocket keeps all your essentials—headlamp, watch, glasses—right at hand and easy to find in the dark
    • Differentiated drawcords (1 round, 1 flat) let you adjust hood and neck easily in the dark
    • Sleeping bag features premium 750-fill-power goose down insulation, a downproof polyester ripstop shell and a soft polyester taffeta lining
    • Pad loops provide attachment points to keep your sleeping bag and pad together to avoid rolling off onto the cold ground (straps sold separately)
    • Efficient, slim cut keeps the weight down
    • Comes with stuff sack and large cotton storage bag
    • Overstock