The Ultimate Guide to Sleeping Bags

General Notes

• We choose what we carry based on extensive research on what's the best value to our customers (e.g., price given performance & durability features) across all the top brands. We specifically do not carry every brand & model; for details on why we do/don't carry certain items in the following What To Use & How To Choose section
• Buy prices are MSRP with tax, i.e., what you see is what you pay. Prices may differ in-store due to change in models or discounts, but this is rare. If we don't sell what we rent, we list MSRP value with tax
• Rent prices are the starting prices; enter trip dates on our Catalog to get exact prices (based on total trip length, not per day!). We also don't charge sales tax, an automatic savings of almost 10%!

Temperature	0F/ -18C	15F or 20F/ -9C to -6C		30F/ -1C
	Mountaineering & expeditions	Standard for most camping		Really warm nights & indoors
Model
	Marmot Never Summer	Marmot Trestles	Marmot Sawtooth	Marmot Trestles	Marmot Never Winter
Buy MSRP with tax	$304	$162	$259	$151	$216
Rent	$22+	$15+	$22+	$15+	$22+
Online rental Catalog name	Sleeping bag (backpacking)	Sleeping bag (regular)	Sleeping bag (backpacking)	Sleeping bag (regular)	Sleeping bag (backpacking)
Material	Down	Synthetic	Down	Synthetic	Down
Weight Standard 6ft (1.8m) height	3lb 3oz 1450g	2lb 7oz 1077g	2lb 8oz 1150g	2lb 1oz 920g	1lb 14oz 850g
Carry size & notes	Slightly bigger than a standard 11L bear canister	Like a kitchen stockpot	Like a standard 11L bear canister	Like a standard 11L bear canister	Like a soccer ball

We do carry gear designed specifically for women (some differences mentioned throughout this guide); however, in our experience, most people do not notice the differences; i.e., actual fit & personal preference are more important than industry-average differences based on sex (e.g., not all women are shorter). Whenever considering sex-specific gear, we recommend comparing all the options, to ensure the price difference is worth it (women-specific items are often more expensive). If you do require a specific sex when renting online, please write-in on the Options page of our online order form; otherwise we will pick regardless of sex. For this gear, women-specific items available in the regular-weight, 15-20F or 30F temperature models, & are either 5.5ft (1.7m) or 6ft (1.8) long.

When you rent online, we will pick a model for you. You can change the model if you pick-up in-store, subject to availability. On the Options page of our online order process, you can also select options or write-in any preferences. This section describes the majority of our models & options, but sometimes we carry others. We will only pick something else if it doesn't conflict with your choices indicated on the Options page; moreover, if there's a major functional difference (e.g., capacity), we will attempt to contact you first

Key factors

Cool zippers, new waterproofing, etc... sometimes it's easy to get lost in all the hype (over-spending happens on features). Our guide focuses on the fundamental factors you should always keep in mind (thus, this short list is similar across all items). Then only at the end do we have some questions to get you thinking about other minor features.

• Type or Style
• Price
• Warmth
• Capacity (size)
• Weight & size (for backpacking)

We highly recommend reviewing Type or Style first, where we review what you can use to address the Core function--a regular item you have at home may work! The other factors are secondary & depend strongly on the Type or Style you've picked.

While we encourage you to use regular items wherever possible, as an outdoor gear shop, we only carry outdoor-specific products

Type or Style

We've organized the most commonly used items people use to address the Core function below, with example images, characteristics, features, etc.

With sleeping bags, there are 2 primary dimensions that you should consider in terms of type or style.

Name		Regular bedding		Sleeping bag
		Blanket	Duvet/ comforter	Rectangular bag	Mummy bag
		Single sheet of material	Two sheets of material with insulation in-between	Think of a duvet folded in half & stitched together (can often be fully unzipped into a small duvet)	Think of a duvet cut & stitched to fit snugly around your body including a hood. Zipper doesn't go all the way down, creating a 'foot box'
Example images
Effect on secondary factors For sleeping bags, data for adult sizes only, more info on youth in Capacity	Price	$20-100	$40-400	$60-150	$80-700
	Warmth Given shape-only	No comparable temperature rating Not enclosed, so doesn't keep out drafts & may create excessive dead air		Rated at discrete temps from 30F to 45+F (-1C to 7+C) Enclosed, but not always form-fit so there can still be some drafts & excessive dead air	Rated at discrete temps -30F & below to 40F (-34C & below to 4C) Form-fit to minimize drafts & excessive dead air
	Capacity	Twin to king size		Generally singles for individuals Though there are some doubles, which is roughly the size of twin-size bedding
	Weight For size analogies, see below	Lighter & smaller	Heavier & larger	2-7lbs (0.9-3.2kg)	1-4lbs (0.5-1.8kg)
	Rationale	N/A		Less warm = less technical, which is why it's used in milder or indoor settings (more ideal for higher temperatures)	More warm = more technical, which is why it's used in colder settings (more ideal for lower temperatures)
Why we do/don't carry it = we rent = we sell		Not specific enough for outdoor use		For rent for sleepers who need extra capacity; Extremely limited availability, please call to reserve	Standard for most outdoor uses

With any of the form factors above, a difference of insulation material is also significantly important. (Note, if you've read our guide on clothing, both of these materials are of the lofting filler technology, i.e., the synthetic doesn't refer to fleece! The reason is because lofting fillers have better warmth-to-weight ratios, e.g., wool sleeping bag of the same warmth as a down one would be too heavy & bulky to bring outdoors.)

While these factors affect any type or style, we've only gathered specific data for sleeping bags. Blankets or duvets/ comforters are more familiar to most people & are also not optimized for the technical factors we'll consider below (e.g., warmth or weight & size)

Capacity (size)

How many people fit in a sleeping bag

Most sleeping bags are designed for single, individual sleepers, since that's the best way to optimize for insulation to minimize drafts & dead air (if insulation didn't matter because it's very hot, then a blanket or duvet may be fine!). That said, there are double sleeping bags (or sometimes 2 single sleeping bags can be zipped together, see Usage section). Here's how a double bag affects the other factors:

• Warmth: given that it isn't as optimal for insulation as a single bag, you're probably not taking a double bag to extreme cold places. Temperature ratings generally are rated 15F/ -9C & above
• Weight & size: more material = greater weight & size
• Price: unfortunately no special deals here, most double sleeping bags are priced like 2 individual sleeping bags

Since it's less versatile & around the same price as 2 individual sleeping bags, most people don't get a double bag. For that reason, we don't have detailed data, nor do we carry this item.

How big the sleeping bag is

Remember that for insulation reasons, it's generally more important to find a bag that fits you just right to minimize drafts & dead air, rather than something that's roomy & more comfortable (e.g., for people who toss & turn a lot). This is a trade-off each person should figure out for themselves via experience. If you decide to go with a roomier bag & feel cold, check out the Usage section for some tips on keeping warm.

Girth: We can have the same table as above for the width dimension, or more accurately, girth--the circumference of the bag on the inside. However, girth differences are less standardized & usually people who get the right height bag find the girth to be appropriate, so we do not present detailed data here. A few guidelines to follow:

• Just like how there's an "Adult long" length size, there's often an extra-wide girth size for people who need more space. Sometimes though extra-wide bags only come in "Adult long" (unfortunately for people who are very tall & very thin)
• For mummy bags, girth is measured in 2 places: around the hips & the shoulders. It's possible to have a bag that's better fit in one place than another
• Rectangular bags, because they're not form fit, generally are roomier than even extra-wide bags, and may be the best option for larger people (not to mention they can often unzip into a blanket)

An extra-wide bag, like a longer-than-standard bag, may incrementally increase price & weight over the standard size by up to $20 & 5oz (142g). We do carry extra-wide (and rectangular) bags for rent for people who need the extra space; extremely limited availability, please call to reserve.

Warmth

In the US, most sleeping bags are marketed as Product + Temperature rating in Fahrenheit . E.g., the Marmot Trestles 15 is a Marmot Trestles sleeping bag rated to 15F/-9C. On our catalog, our sleeping bags follow the convention of using the manufacturer's marketing temperature rating! This temperature rating tells you the ideal temperature in which the manufacturer believes this bag is suited for. This means that the temperature rating is inversely related to the bag thickness; i.e., the lower the number, the thicker the bag. For example: bag rated for 0F/-18C is thicker than (designed for a colder temperature) a bag that's rated 15F/-9C, which is itself thicker than a bag that's rated for 30F/-9C (designed for a warmer temperature).

While it seems really straightforward to just lookup the temperature forecast where you'll be camping, and get the appropriate sleeping bag, here are a few complexities:

1. Sleeping bags may have 4 distinct temperature ratings; know what you're looking for!. Generally, women tend to be cold-sleepers & men tend to be warm-sleepers. So, a 15F/-9C bag... is that good for a woman at that temperature (in which case a man might find it to be too warm/ too thick), or good for a man at that temperature (in which case a woman might find it to be too cold/ too thin)? Recognizing this conundrum, the European Union attempted to standardize temperature rating with a set of 3 EN ratings printed on the bag (see definitions below). So a Marmot Trestles 15 bag will also tell you that it's EN comfort is 27F/-3, EN limit is 16F/-9C, and EN extreme is -17F/-27C. In this case, the marketing temp rating is closest to the EN limit, but this won't always be the case; manufacturers follow their in-house testing to set their marketing rating, so there's no formula to translate the marketing rating to EN rating, though you should expect the marketing rating to fall within the range of EN limit to comfort +/- a few degrees.
• EN Comfort rating: the lowest temperature at which the bag will keep you comfortable if you are an average cold-sleeper (likely to be a woman)
• EN Lower limit rating: the lowest temperature at which the bag will keep you comfortable if you are an average warm-sleeper (likely to be a man)
• EN Extreme rating: (less commonly cited) the lowest temperature at which the bag will keep the average warm-sleeper alive (yes it's a bit... extreme!)
2. The sex-based differences above are still based on averages. Like any decision around insulation & warmth, personal preference can be much more important than statistics & actual conditions. We've had customers rent 30F/-1C (what would normally be a summer bag) to go mountaineering; and we've had customers getting a 0F/-18C bag for summer camping! The great thing about renting is you can experiment with what works for you
3. Temperature ratings often assume you are wearing base layers & are using a sleeping pad (i.e., skipping either means the temperature rating is more generous, and you may be colder)

Because it's not so straightforward, especially for more beginners without the experience of trying various bags, we generally recommend a sleeping bag rated to at least ~10F/5C lower than the actual night time temperature forecasted, sometimes even more (some people recommend a rating up to ~25F/13C lower than forecasted temperature). I.e., if the temperature forecast is 40F/4C, you should have a bag that's rated to at least as warm as a 30F/-1C bag (in this example, a 15F/-9C bag is thicker and might be better for someone who knows they tend to be colder at night). Here's a more practical guide using activity examples, and so you can also see how the bag temperature affects other factors like weight & price.

Weight & Size (Compactness) for Backpacking

If you're thru-hiking 20+ miles (32+km) per day, every advantage counts! In this case, size refers to compactness. You can carry more gear in the same size backpack if all of it is very compact, or for more weight savings, you can get a smaller size pack.

To reduce more weight & increase compactability, manufacturers reduce the amount of material used (e.g., fewer features, thinner fabrics, etc.) and, where possible, use more technical materials to prevent performance loss. For example, ultralight fabric used in clothing has to still be waterproof. These strategies create 2 general consequences

• Lightweight gear tends to be less durable: Sometimes, light-weight gear is just thinner & so more prone to damage (even a more technical material may not fully offset the loss in durability)
• Lightweight gear tends to be more expensive: While less materials = lower cost, the more dominating effect is often that thinner materials = more technical = greater cost

For these reasons, the lighter the gear, the more you should treat it as an investment! Is the price difference worth the weight or size savings? This depends on you & your trip.

Minor features that may be important

Here, we give you a list of questions to start thinking about minor features. We hope our approach of savings these features for last gets you to more critically think about what you need & not get caught up in the hype of what's cool and over-spend your budget.

• Is there an internal pocket?
• How are the zippers placed? (It can be hard to get in/out of a bag, some people find zipper placement helps)
• Is there a drawstring so you can pull the hood tight enough that only your nose & mouth are showing? (this depends on fit with you specifically!)
• Can it integrate with a sleeping pad? (Some sleeping bags have sleeves so you can put a sleeping pad inside, helping stop you from rolling off the pad)

Pairing with a sleeping pad

Your weight will compress the sleeping bag at your backside to the ground, which means at your backside, the sleeping bag doesn't insulate that well (review the insulation info at the top of the page for more info)! That's why a sleeping pad is so critical. Beyond providing comfort, a sleeping pad is the second half of your outdoor warmth system, since it provides insulation from the ground. As we mentioned, EN temperature ratings already assume you're using a sleeping pad, so if you're not, the ratings will feel too generous. Some brands also make single sleeping systems, either consisting of an integrated bag + pad combo, or a sleeping bag with a slot on the bottom designed to fit a sleeping pad & keep it in place. These integrated systems are great, but keep in mind the trade-off is versatility (e.g., swapping out sleeping bags or pads based on the temperature & weight requirements).

The stuff sack

When you buy a sleeping bag, it usually comes with 2 sacks. One is large, generally mesh, this is used for storage at home (see Maintenance section). The other that's smaller & may have strapps around it, is used to bring your bag on your adventure. How do you get a big bag in such a small sack? Don't roll, just stuff (starting from the foot box so that air is squeezed out as you go)! Sleeping bags are designed to be compressed so stuffing doesn't damage anything & it's far easier than a neat roll. If your stuff sack has straps around it (called a compression sack), you can pull on the straps to compress it even smaller.

Once you're ready to sleep, you can then fill the empty stuff sack with clothes to double as a pillow! In fact, some stuff sacks even come with a soft velvet side designed for this use.

Keeping dry

Although the outer shell of a sleeping bag is often treated to be water-resistant, it's always important to keep a bag dry, since, depending on its material, its performance may be impacted. In addition to keeping the sleeping bag inside a waterproofed backpack or tent at all times, you can also think about stuffing it into a trash compactor bag & then into your stuff sack, or using a waterproof stuff sack.

Regulating temperature

Firstly, make sure your bag is at optimal performance! We recommend taking it out once camp is set up to let it re-loft while you hang out. You may also want to beat it to help it loft up (like you'd do to a pillow or blanket to fluff it). Review the insulation info at the top of the page for more info.

Even if your bag is at optimal performance, it may not be best for you or the situation, so here are a few tips on what to do if...

You're too cold (e.g., the bag isn't thick enough)

• Wear more layers or use a sleeping bag liner. Create more layer(s) of dead air closer to your body within the bag
• Plug up the excessive dead air. So you don't have to waste energy heating it. For example if a bag is too long, fill up the bottom with clothes or tuck it under you
• Add an additional 'heat generator'. Put in a hot water bottle
• Do some crunches in the bag. Physical exertion generates more heat than just lying there
• Add another sleeping pad. Some sleeping pads can layer, and this would create another barrier between you and the ground, which is great at sucking away body heat

You're too hot (e.g., the bag is too thick)

• Take off layers. Trap less dead air around you
• Unzip the bag. Bring in some air flow to get rid of some body heat
• Remove the sleeping pad. This is a trade-off in itself, since sleeping on the hard ground can be very uncomfortable

Unfortunately in both cases, there are physical limits. You can't layer up forever if you're too cold--at some point, the excessive layering compresses the insulation material of the sleeping bag. You also can't take off more layers if you're already naked, and often, the reality of unzipping is that it leaves you half cold, half hot. Only experience will help you fine tune, so treat any mistakes like a learning opportunity, and get pumped for your next trip!

Sleeping with partners (double bags)

Double sleeping bag

Sometimes has a single hood (as shown), sometimes has two

Zipping 2 sleeping bags together

Can be awkward with 2 hoods & 2 foot boxes, but if you'd like to try, a few tips:

• The bags don't have to be the same lengths, but the zippers should be (otherwise the bags won't zip up fully). This often means getting bags from the same brand or model
• Zipper tracks need to be on opposite side of the bag (as shown)
• Each zipper track must have 2 zipper sliders pulls

Repairing

We can either provide parts or repair services in some capacity for the following; check our Gear Repair page for details:

• Zippers
• Holes, rips, or tears

Cleaning & Storing

Gear not in use should be cleaned & dried and then stored loose & in a dark environment, check out our entire protip on the topic here.

We have a general protip on how to store & maintain gear that we highly recommend reviewing as well. If you send us video or a good photo series, we may be able to help you evaluate your repair needs.

A super astute reader (or the really dogmatic lightweight hiker) may have realized--wait, the bottom of my sleeping bag doesn't insulate well, which is why I need a sleeping pad... so then why don't I just cut off the bottom of the sleeping bag, save the weight & the money? Yup they've done that, it's called a backpacking quilt (not at all like your grandmother's, unless she was an ultralight hiker)! You can imagine, with a quilt, it's then critical to have a sleeping pad on the bottom. Also you'll want to take greater care (some quilts have straps for this) to reduce drafts, since a quilt won't fully enclose you.

A hammock can potentially substitute for your entire essential set of tent, sleeping bag, and sleeping pad! Substitutability depends on the model of hammock, so do your research thoroughly to see if the hammock has rain protection or mesh (to simulate a tent), and any built-in padding or bedding for warmth & comfort. You'll also want to ensure there are plenty of trees where you're going. Finally, you might want to try taking a nap first, hammocks result in back pain for some & back pain relief for others, the last thing you want is to wake up after a long night in pain!