Sleeping Bag Loft and Temp Rating

pstm13

Auribus Teneo Lupum
.
Joined
Dec 27, 2012
Messages
570
I was not able to get any nights in really cold weather this year to test out my thickest sleeping bag. So I thought I would ask if anyone has experience in weather between -10F and -30F. How much loft do you need in a bag made of down fill to be reasonable comfortable? This is assuming of course a quality bag with baffles and a mummy hood.

I have done some research in cyber space on the interweb and it seems like they over state how warm a bag is going to be. I have only been down to 0 in a crappy synthetic bag and my full snow suit underneath several years ago. I was not a happy camper. I have since upgraded but have not been able to use my bag(s) in anything lower that +15.

Thanks in advance
 
Last edited:

Wyatt Carson

Desert Vagabond
Joined
Apr 15, 2015
Messages
304
Though I have lived in areas that regularly got down to -40 on the Turtle Mountain Plateau, I don't have any first hand experience with camping in it, just hiking... LOL

but since nobody has answered your query I do have experience with Western Mountaineering bags and have three of them that seem to be close to their ratings to me anyway. Part of it is going to be how snug the bag fits and if it has a hood but you can get a glimpse with Western Mountaineering's charts of what they think. Usually they are considered fairly conservative in their ratings. The Cypress has 10.5 inches of loft and they rate it at -30. For me in a tent and a couple of closed cell foam pads underneath, maybe...

I have their Sequoia 5 degree bag and mostly use it for around 15 degrees. My 25 degree Sycamore gets more use because fall and spring are the seasons I like to be out and will look for milder weather and temps now. Both of those bags are wide taper, not mummy bags. Mummy shape will be easier for your body to keep warm but I like a roomy bag.
 

Outdoor_Fool

Member
.
Joined
Dec 11, 2015
Messages
1,724
It seems that back in the day, most bag makers were more honest with their bag ratings. Maybe that's because I slept warmer then and a -5 F bag would keep me warm to -5 F. I remember reading how most reputable bag makers tested their bags using some device, a human like copper mannequin filled with warm water to see if their bag rated at whatever temp would actually keep it warm at that temp. I'm not sure if anyone uses that anymore. Anyway, back then, 10 inches of loft seemed to be the norm for minus 40. Some friends have -40 down bags for their spring treks up here and they seem to have about 10 inches of loft. My old -40 synthetic bag was in that neighborhood also. It was a NF mummy bag and so tight that I preferred not to use it. I would use my -20 and a fleece liner and be fine down to -40 or so.
 

pstm13

Auribus Teneo Lupum
.
Joined
Dec 27, 2012
Messages
570
Thanks guys. That's about what I was thinking. Thanks for your input. I have a few bags that range from 8-12 inches of loft. The thickest is an old Eddie Bauer Kara Karom that measures in @ 12". The down side is that it lacks baffles on the chest. I just hope I never have to test it out at or below -20.
 
Similar threads
Thread starter Title Forum Replies Date
Adr1an +5 C° comfort temperature sleeping bag Gear 12
Yvonne Below Zero Winter Sleeping Bag Gear 18
Perry Anyone Have any Experience with Sierra Designs Nitro 800 0-degree Sleeping Bag Gear 11
Pianomover Sleeping bag liners. Gear 40
D Western Mountaineering sleeping bag recommendations plz General Discussion 5
Tystevens What is your sleeping bag lineup? Gear 23
kimbur96 Winter sleeping bag? Gear 17
AKay09 Sleeping Bag Thoughts Gear 9
balzaccom Sleeping bag maintenance Gear 4
Spencer Sutherland Long Sleeping Bag Gear 7
Mike K Sleeping Bag Repair (With Tape) Gear 7
natylka Advice on the best lightweight sleeping bag for backpacking. Gear 27
TrektheWorld Kids/Child Sleeping Bag ?? Gear 9
mtjack Late Fall/winter sleeping bag Gear 2
IntrepidXJ 0 Degree Semi-Rectangular Down Sleeping Bag? Gear 15
Nick Sleeping Bag Alternatives Gear 23
Tyler Gear Review Kelty light trekker 20 degree down sleeping bag Gear Reviews 12
HomerJ Gear Review Mont Bell U.L. Super Spiral #1 - Sleeping Bag Gear Reviews 0
pixie1339 Sleeping bag help Gear 43
Adr1an Deuter: sleeping bags versus backpacks Gear 0
Miya Beach Backpacking and Creek Bed Sleeping Backpacking 29
Ugly Sleeping with Pfieff, Maybird in May, or Summer -Winter Backpacking Winter Sports 7
Born to Hike Can the Therm-a-Rest NeoAir XLite Sleeping Pad be used for this? Gear Reviews 5
T RMNP sleeping pad question- mid July Trip Planning 4
Vegan.Hiker New sleeping platform for my car General Discussion 9
Kelley Another Sleeping Pad question. Gear 5
Miya Water Resistant Down Sleeping Bags? Gear 36
Lincsco Sleeping pads for side sleepers Gear 17
Wanderlust073 Sleeping Pads Gear 49
N Sleeping bags for 2 Gear 8
Outdoors24 Sleeping Pad! Gear 9
andyjaggy Sleeping General Discussion 37
uintahiker Patching Sleeping Pads & Air Mattresses Gear 23
DrNed Nemo Astro Air Ultralight Sleeping Pad Gear 6
Eugene Sleeping bags Gear 23
Tater Head Now entering the ring... (sleeping pads) Gear 44
TheDunedain Sleeping ute access? Trip Planning 2
K Recommendations for sleeping bags/pads on a college student budget? Gear 15
Aldaron Sleeping Pad Straps Gear 7
Deadeye008 Klymit sleeping pads sale Gear 0
Deadeye008 Gear Review Klymit Static V Sleeping Pad Gear Reviews 3
Udink Bag Night Challenge 2021 General Discussion 29
IntrepidXJ Bag Night Challenge 2020 General Discussion 99
fossana lightweight *waterproof* dry bag recommendation? Gear Reviews 13
Mikjik86 Waterproof backpack bag for packrafting? On The Water 7
Artemus Bag Night Challenge Results Summary General Discussion 0
Artemus Bag Night Challenge 2019 General Discussion 225
westy OR Bag Cover and Alico boots Gear 0
Jackson Bag Night Challenge 2018 General Discussion 454
Perry Experience with ZPacks Cuben Fiber Bear Bag Kit? Gear 6

Similar threads

Don't like ads? Become a BCP Supporting Member and kiss them all goodbye. Click here for more info.

Top