Our Guide to Sleeping Bags

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 other factors	Price	$20-100	$40-400	$60-150	$80-700
	Size (Capacity)	Twin to king size		Generally singles for individuals Though there are some doubles, which is roughly the size of twin-size bedding
	Weight	Lighter & smaller	Heavier & larger	2-7lbs (0.9-3.2kg)	1-4lbs (0.5-1.8kg)
	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
	Material	Cotton Synthetic (e.g., fleece) Wool	Down Synthetic lofting filler (more similar to down than fleece) Wool	Down Synthetic lofting filler (more similar to down than fleece)
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 write-in a special request when you reserve	Standard for most outdoor uses

For sleeping bags, data for adult sizes only

If you don't go very often, of course you're going to want to spend less money, but this often means real trade-offs in terms of the experience that you will have with the gear. Even if you do go often & are ready to invest in quality gear, having the upfront funds can be hard!

Now, it may seem like this price & quality trade-off is disappearing, because you can find a cheap version of almost anything for tens of dollars that still has good reviews (assuming the reviews are real). So you might be thinking: I'll just buy something cheap, and because the price is so low it doesn't matter if it's less featured or heavier or whatever compared to something higher end. When that breaks, I'll buy something cheap again, and so on. Just remember:

• What's better than cheap? FREE! And we have a gear library of items you can borrow for free!
• Many reviews are written after only a trial use or first use: We've seen entire review videos of gear done at home, which is very different than actually being outdoors! And reviews after the first use don't tell you about durability at all
• You're headed outdoors to relax and enjoy life! Saving money only to have a trip ruined due to quality issues will feel terrible. Our program to rent sleeping bags is designed to help you avoid this trade-off: you get to rent high end, quality sleeping bags for around the same price as buying cheap ones (sometimes even for less!)

For this item specifically, the price vs. quality trade-off issues center around performance & durability.

• The sleeping bag was bigger or heavier: A 1lb or 2kg difference may not matter on a 3 hour hike, but it might on a 6 hour hike! Not to mention you might need to spend more on a big enough backpack to carry it
• The sleeping bag leaves you cold: We talk more about Warmth below. Lower end brands don't standardize their temperature ratings & are frequently overly generous; some reviews have said a 0F bag felt like a 40F bag!
• The sleeping bag wasn't very waterproof or durable: Waterproofing is a bigger concern for down bags, which don't insulate well when wet. Durability is really important for zippers. Higher end bags have features that prevent zippers from snagging & breaking. This may seem like a small issue, but if a bag can't be zipped up it won't insulate! Fabric-wise, lower end items tend to be made with polyester, which is less durable than nylon (more info in our clothing guide, see section on Durability); and of course, if the fabric tears, performance is compromised. Finally lower end items may not have or may have less effective waterproofing

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 (compactness): 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, which can be made easy by renting sleeping bags of different sizes. If you decide to go with a roomier bag & feel cold, check out the Usage section for some tips on keeping warm.

Length (height of person)

Width (girth of person)

Technically, we could have the same table as above for 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 write-in a special request when you reserve.

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 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! Given our mission we're the only shop that rents a sleeping bag that's ultralight, so feel free to try it out, and see how different the weight feels!

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/-1C (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. Honestly the best way to figure out what your warmth preferences are is to rent a sleeping bag of different ratings and figure it out via trial-and-error!

Material strongly correlates with Weight & Size (Compactness) for Backpacking which was previously discussed above. All of our regular sleeping bag rentals are synthetic while all of our backpacking sleeping bag rentals are down. We're also one of the few shops that will rent down sleeping bags, so it's a great chance to try it, and see how the difference in material and weight & size feels for you.

*Synthetic lofting fillers' fibers will break over time, impeding their ability to loft. With proper care (e.g., not prolonged compressed storage), down fibers can last much longer

**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.

Here, we give you a list of questions to start thinking about other 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. Remember, we allow you to hire a sleeping bag so feel free to try out various models with different features.

• 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)

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).

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.

Although the outer shell of a sleeping bag is often treated to be water-repellant, it's always important to keep a bag dry since its performance may be impacted when wet (see Material section). In addition to keeping the sleeping bag inside, you can also think about stuffing it into a trash compactor bag & then into your stuff sack, or using a waterproof stuff sack.

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!

Because of the trade-off between roominess & insulation (see Size (Capacity) section), it's often not a good idea to sleep with a partner; not to mention, you & your partner may have very different sleeping preferences in terms of temperature.

If you'd like to do so anyway, for 2 adults there are two options, see below. If you're looking to sleep with a baby or small child, sometimes, depending on their size, it may be ok to use a single bag.

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, we recommend renting sleeping bags that zip together from us to give it a try first. Write-in this request online, so we can prepare the right bags, where:

• Zipper tracks are the same lengths (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