Selecting the Right Sleeping Bag for Backpacking Adventures

When I first began backpacking, selecting the right gear felt incredibly daunting. It seems simple at first—just pick a sleeping bag, for example—but you quickly realize there are dozens of tiny decisions involved, each with its own complexities that can make your head spin. So how do you even begin?

By identifying the environments where you’ll typically be backpacking, you can follow this guide in reverse to determine the ideal bag for your needs. While other elements—such as base layers and sleeping pads—can influence your sleep system, this guide offers a reliable foundation to begin your search.

Settling in for the night along the CDT in Colorado with my Zpacks Classic 5 degree sleeping bag.

How to decide between synthetic and down sleeping bags

When choosing a sleeping bag, one of the initial choices is whether to opt for down or synthetic insulation. Both options have advantages and drawbacks, but down is typically the preferred choice for long-distance backpacking. To see why, consider the benefits of down sleeping bags. Most notably, down provides superior warmth relative to weight compared to synthetic alternatives. It offers the most efficient lightweight insulation available. Additionally, down compresses more tightly, saving space in your pack and leaving room for essentials like food. With proper maintenance—such as correct washing and storage—a down sleeping bag can also outlast synthetic models, delivering reliable performance for many years.

You might be wondering, are down bags flawless? While they’re excellent, they do have some downsides. A significant issue is that down loses its insulating properties when wet. If your sleeping bag gets drenched in a downpour, you’ll need an alternative for the night. Using proper shelters and backpacks can help avoid this, but it’s something to consider if you’re trekking in persistently wet and chilly environments (like the late shoulder season in the North Cascades). Down bags also demand careful upkeep—they need specialized detergents for washing and shouldn’t be stored compressed. Additionally, down is pricier than synthetic, though with proper care, it offers long-term durability. Lastly, down isn’t an option for those with allergies to it.

This highlights the advantages of synthetic insulation. Compared to down, the synthetic materials in sleeping bags repel water and retain warmth even when damp. As a result, down bags are perfect for situations where exposure to moisture is likely. Additionally, synthetic bags tend to be less expensive than down-filled ones, since their materials are more readily available—eliminating the need for geese or ducks. Moreover, synthetic is the better choice for those with allergies to down.

That said, synthetic filling naturally comes with its own drawbacks. It provides less warmth and adds more weight. Its bulkier nature makes it unsuitable for backpacking, where minimizing weight and saving space are key concerns. Additionally, synthetic insulation is far less durable than down—its insulating capacity gradually diminishes with each compression.

What should a backpacker choose? If your budget allows, opt for a down bag and be diligent about keeping it dry, especially in rainy environments. My preferred method is using a trash compactor liner inside my pack—it’s lighter than dry bags and just as effective.

TLDR:

Down

Pros:

• Lighter for reduced mass

• Compresses with ease

• With proper maintenance, it can remain in good condition for many years.

With proper care, it can remain in good condition for many years.

Cons:

• Loses insulation properties when exposed to moisture

• Necessitates specialized upkeep

• Possible allergic reactions to consider

• Costlier

Synthetic

Pros:

• Able to repel water to some degree

• Maintains insulation even when damp

• Hypoallergenic

Cons:

• Cooler temperatures for greater mass

• Large and cumbersome

• Less resilient (diminishes insulating capacity with prolonged use)

Spending the night at Capitol Lake with my Katabatic Sawatch 15-degree quilt.

Deciding whether to opt for a quilt or a conventional sleeping bag

Over the past few years, quilts have surged in popularity among backpackers. They’re innovative, trendy, and, most crucially—they offer a way to reduce your base weight by a few ounces. But what precisely ARE they? And how do they differ from traditional sleeping bags?

A quilt functions similarly to a down blanket. It eliminates the back section of a sleeping bag, which typically compresses under your body and offers minimal warmth. By removing this excess insulation and fabric, a quilt lightens your pack without sacrificing much—if any—heat retention. Many quilts feature snug foot boxes and additional straps to secure you inside and partially attach to your sleeping pad, minimizing drafts and ensuring warmth throughout the night. That said, designs vary, and some quilts may be prone to drafts, so checking reviews before purchasing is advisable.

Since everyone likely knows what a typical sleeping bag looks like, I’ll keep it short. The key distinctions are between mummy bags (featuring enclosed hoods) and non-mummy bags. Mummy bags excel for winter camping and for campers who prefer a tight, cozy fit, though the additional fabric does increase the overall weight.

No matter the circumstances, conventional sleeping bags will zip completely shut and invariably feature enclosed foot compartments, reducing the likelihood of drafts.

The decision ultimately depends on personal preference. If you enjoy being snugly wrapped like an infant while sleeping, you’ll probably lean toward the mummy bag side. On the other hand, if you prefer the flexibility to kick a leg out from under the covers, a quilt might suit you better. Many suggest that quilts are ideal for restless sleepers, but I disagree—this can create drafts, making a conventional sleeping bag a more reliable choice. While quilts may sometimes save a bit of weight, it’s not guaranteed.

Sleeping under the stars in the Grand Canyon with my Katabatic Sawatch 15 degree quilt.

Selecting the right temperature rating for your sleeping bag

A temperature rating specifies the minimum temperature at which a sleeping bag can keep an average person warm. For instance, a 5-degree bag is designed to provide warmth at 5 degrees but not below. It also means a 5-degree bag offers more insulation than a 30-degree model. As a beginner backpacker learning about temperature ratings, I noted two important points—standardization of these ratings matters (more on that later), and it’s helpful to know how your own comfort compares to the average sleeper. In my case, I tend to feel cold easily. I often start shivering quickly and need a bag rated 20-25 degrees lower than the actual temperature to stay cozy. While I could technically endure the rated temperature, we’re not outfitting for survival; we’re aiming for comfort (ideally). So, for example, to sleep comfortably in 30-degree conditions, I’d choose a 5-degree bag.

Let’s discuss temperature rating standards, as none of this matters if sleeping bag manufacturers simply assign arbitrary temperatures to their products. The two primary standardization methods are EN (European Norm) and ISO (International Organization for Standardization). These widely recognized systems typically provide a “comfort” rating (ideal for cold sleepers like me) and a “limit” rating (suited for those fortunate warm sleepers who can manage with lighter bags). If a bag lacks one of these standardized ratings, it’s safer to choose a warmer option than usual and thoroughly check reviews. Cooling down by loosening the bag or sticking out a leg is far simpler than enduring discomfort—or even risk—with an insufficiently warm bag.

Appreciate your patience while I covered temp ratings—now let’s dive into the specifics of which temperature ratings to consider based on the season and regions you’ll be backpacking in.

A general guideline (adapt according to your own comfort with temperature variations):

Sleeping bags rated for 20 degrees Fahrenheit or below:commonly utilized in colder climates (winter, early spring, late autumn) and high-altitude environments.

Sleeping bags rated for temperatures between 20 and 32 degrees:Ideal for genuine shoulder seasons and elevated terrains

Sleeping bags rated for 32 degrees Fahrenheit and higher:Utilized during warmer months and in areas of reduced altitude

For an average sleeper seeking a three-season bag (ideal for a thru-hike), opt for one rated between 20 and 32 degrees.

From my own experience—I chose a 5-degree sleeping bag for the PCT since, as I mentioned, I’m constantly cold. It was slightly excessive in some summer stretches, but I’d simply leave the zipper open or treat it like a blanket on hotter evenings. The extra warmth proved absolutely necessary by the time October arrived in Washington.

Cowboy camping along the CDT in the San Juans during late May (included a liner for additional warmth).

Selecting the right fill power and fill weight for your sleeping bag

Fill power and weight are terms specific to down sleeping bags, and understanding these measurements is essential when selecting the ideal bag for your needs.

Fill performancerefers to thequalityThe loft of the down is determined by the volume occupied by 1 ounce of down. A higher fill power indicates a lighter and more compressible sleeping bag.

Net weight of fillrefers to theamountThe amount of down is indicated by the fill weight, which measures the ounces of down in a comforter. This directly influences the level of warmth provided.

Although fill weight primarily determines warmth, greater fill powers enhance insulation efficiency with less weight.

In basic terms: Greater loft between the down clusters improves insulation, resulting in a sleeping bag that’s both lighter and more thermally efficient.

When applying this in practice: if you’re personalizing a bag designed for 10-degree conditions and deciding between 850 and 950 fill power—the 950 fill power will achieve a 10-degree rating with less fill weight compared to the 850 fill power option.

Selecting the right size for your sleeping bag

Selecting the right sleeping bag size is simple (refer to the gear company’s sizing guides), though there are some helpful tips to consider.

The ideal length depends on your height, though stomach sleepers should account for a few extra inches.

Width is calculated based on, as you might expect, your body’s width—usually by measuring the broadest section (with your arms resting naturally at your sides). If you tend to shift positions frequently while sleeping, remember to include a couple of extra inches for comfort.

Pro tip: because many cottage gear brands are sold exclusively online and it can be tough to picture what will truly be comfortable, you have two options: 1) visit a retailer such as REI to try out bags in person (and jot down their dimensions) or 2) use safety pins to adjust a sheet at home and experiment with different widths to gauge comfort.

How to select a sleeping bag considering weight and price

This is where things become a bit tricky. Nearly every decision you make will influence these two critical factors. An ideal weight for a down backpacking sleeping bag is less than 2 pounds, though lighter options usually come at a higher price. In my opinion, it’s worthwhile to invest in high-quality gear you’ll truly enjoy, since purchasing one $400 bag is more cost-effective than buying three $150 ones.

The most affordable bags are usually heavier synthetic options, whereas lightweight down bags tend to be more expensive.

If you’re just starting out with backpacking and hesitant to invest in a high-end, 950 fill power, 10-degree, $400 down sleeping bag—check out second-hand alternatives on Facebook Marketplace or resale platforms. Certain cities also feature gear consignment shops offering quality used equipment at budget-friendly rates. Additionally, planning ahead allows you to take advantage of sales events (Black Friday is an excellent opportunity to purchase off-season gear).