Choosing the right down sleeping bag.
Over fifty years of crafting bags has taught us this: there's no single bag that does everything. This guide walks you through how to choose between the array of sleeping bags we make, from the exceptionally light 15-oz Vireo to the warmest -60°F Snowy Owl.
The 30-second quick start.
If you're shopping today, the answer to "which bag" almost always falls into one of three buckets. Pick the one that matches your trip and skip ahead, or keep reading for the full picture.
Three-Season
Spring, summer, fall. Backpacking, thru-hiking, alpine. The most popular category and where most buyers start.
Winter Light
Shoulder-winter, snow camping, ski touring. Same ultralight philosophy, dialed for colder nights.
Winter & Expedition
Denali, Everest, Antarctica, you name it. Built for the harshest conditions on Earth, with no compromises.
Temperature is the start
Since you're probably looking for a sleeping bag expressly in order to stay warm, it's no surprise that temperature is the primary factor in selecting a sleeping bag that is right for you. As a rule, it's a good idea to select a sleeping bag that is rated to a temperature slightly below what you expect to encounter. Hearty climbers and thru-hikers may be willing to utilize other insulating layers to extend the comfort range of their bags.
We recommend choosing a bag rated about 10°F (~5ºC) below the coldest temperature you actually expect. If you sleep cold, we recommend going 20°F (~10ºC) below. Although our sleeping bags are conservatively rated, many variables can affect your warmth. Always pick warmer than you think.
Shape affects warmth.
A snug bag is warmer per ounce because there's less air to heat. A roomier bag is more comfortable but costs you weight and warmth efficiency. The right shape is the one that matches how you sleep. We make a variety of sleeping bag shapes so there is something that suits you and your adventures.
Narrow Mummy
For gram-counters and slim builds. The most thermally efficient cut with minimal dead space to heat.
Shop Narrow Mummy →
Standard Mummy
Room to move without sacrificing warmth. The default for most three-season and winter buyers.
Shop Standard Width →
Wide Mummy
Side sleepers, broader shoulders, restless sleepers. Mummy efficiency with elbow room.
Shop Wide Width →
Women's Mummy
Warmer through the core, narrower at the shoulders, available in shorter lengths. Extra fill where women typically lose heat fastest.
Shop Women's Bags →
Hoodless Bags
Versatile quilt bags for backpacking, bikepacking, and so much more. Use as a quilt, a bag, or somewhere in-between. The thru-hiker and minimalist favorite.
Shop Hoodless Bags →
Semi-Rectangular
A middle ground for sleepers who hate mummy bags but still want efficient down construction.
Shop Semi-Rectangular →
Rectangular
The Condor sleeping bag. For car camping, basecamp, and anyone who wants to move freely. A modular bag compatible with optional hoods and groundsheet.
Shop Rectangular →
Two-Person
Purpose-built Spoonbill two-person bags for backpacking and basecamp. Or the modular Penguin and Condor systems.
Shop Two-Person →The shoulder-measurement formula
The right shoulder width is measurable, not guessed. Your ideal bag has roughly 10 inches (25cm) of shoulder room beyond your own measurement. That's the breathing room you need to move without creating cold spots.
How to measure
- Wrap a soft tape measure around your shoulders, including your arms at rest.
- Add 10 inches (or 25cm).
- Compare against the shoulder dimension listed on each product page.
For example: 54″ (137cm) shoulder + 10″ (25cm) = 64″ (162cm) bag width. Repeat for hip if you have a meaningfully different hip measurement.
Fabric and Down — the differences.
The bulk of our sleeping bag categories comes in two compositions. The shapes and patterns stay the same; the materials are what change. Below: how UL compares to YF for three-season bags, and how Winter Light compares to ES for the colder end of the line.
Three-Season: UL vs YF
UL Series
YF Series
Winter & Expedition: Winter Light vs ES
Winter Light Series
ES Series
What about fill power?
Fill power measures how much loft (volume) one ounce of down produces. Higher fill power = more air trapped = more warmth per ounce. We use 950+ goose down in our UL series and Tanager, which is among the highest commercially available. 900+ fill power goose down goes in our YF, Winter Light, and ES series. We also offer 900+ fill power Ultrasonic Muscovy™ down in our YF series.
All of the down we use is RDS-certified. Every ounce of down we use is Responsible Down Standard certified, sourced ethically without live-plucking or force-feeding. Each bag ships with a traceability card showing where its down came from and its finer details. Read more about our down →
Length and fit.
Length matters more than people think. A bag that's too long means heat-stealing dead space at your feet. A bag that's too short compresses the down at your head and feet, creating cold spots in exactly the places you can't afford them.
Men's / Unisex
Women's
Two-person sleep systems.
We offer three purpose-built solutions for couples, plus a fourth path for shoppers who want pair-ready single bags. Each design has their virtues. Here's what those are.
Penguin YF
A semi-rectangular bag with all the modular features of the Condor, without the extra bulk and weight of a fully rectangular footbox. Fully unzips and attaches to a matching groundsheet plus optional hoods to switch between one- and two-person configurations.
- Pad fit: Two 20" wide sleeping pads
- Best for: Couples who want flexibility without the heaviest gear
Condor YF
The roomiest single-person bag we make, doubling as a two-person system when fully unzipped and attached to a matching groundsheet. Optional hoods can be zipped on to both the bag (single use) or the groundsheet (double use). For couples who want maximum room.
- Pad fit: Two 25" wide sleeping pads
- Best for: Couples who prioritize comfort and space
Spoonbill UL
The award-winning design and the most specialized bag we make making it the ultimate in weight savings and efficiency for two. The Spoonbill lets two people share the thermal benefit of one bag while keeping independently contoured hoods and collars. The floor is uninsulated to save weight, so you'll need two sleeping pads with a couple kit underneath, or a closed-cell foam pad cut to fit the interior bag floor.
- Pad fit: Two pads with couple kit, or trimmed CCF
- Best for: Weight-conscious couples on backpacking and alpine trips
Flicker Series
This hybrid sleeping bag/quilt fully unzips into a quilt, then zips into another Flicker (cinched at the footbox) to create a double version that accommodates two people. Regular and Wide Flickers are all cross-compatible, with themselves and each other.
- Compatibility note: Current Flickers do not have compatible zippers with Flickers made prior to 2023
- Best for: Thru-hikers, weight-conscious couples, and shoppers who want one quilt that works solo or paired
Most of our bags are zip-compatible.
For couples who want flexibility, a different temperature rating per partner, or who already own one Feathered Friends bags, most of our sleeping bag line up is zip-compatible! You'll need one Men's/Unisex bag (left zip) and one Women's bag (right zip). Our zippers are standardized #5 YKK, so you can mix models (for example, an Egret UL 20 paired with a Swallow UL 30). Flickers are compatible with other Flickers; see the Flicker section above for compatibility details.
Pick your adventure.
If you know what you're doing, not what temperature you'll see, start here. We've grouped our line by the activities they're built for.
Backpacking & Thru-Hiking
The PCT, AT, JMT, and weekend trips. Where warmth-to-weight matters most.
Three-Season Bags →Mountaineering & Alpine
Rainier, Denali, Everest, Cascade volcanoes. Built for high elevation and severe weather.
Winter & Expedition →Bikepacking & Ultralight
The Flicker quilt's adaptability across temperatures makes it the go-to for long, variable-weather routes.
Flicker Series →Women's-Specific
Cut warmer through the core, narrower at the shoulders, in shorter lengths. Available from ultralight to expedition-grade.
Women's Bags →Couples & Two-Person
The Spoonbill UL is purpose-built for two. Or check out one of our modular Penguin and Condor sleeping bags.
Two-Person Bags →Ultralight Bivy
The lightest possible options for those extremely fast and light missions. The Vireo and Tanager.
Minalmist Bags →Eight things that affect how warm you sleep.
The bag is the biggest factor, but not the only one. There are many variables, but these eight factors help explain why two people in the same bag, on the same night, can have wildly different experiences.
Sleeping pad R-value
Your sleeping pad is a very important piece in your sleep system. Sleeping pads prevent conductive heat loss to the cold ground beneath you. The higher the R-value, the more insulated you are from the ground. A pad R-value of 2 to 4 is common for three-season use. Use in colder environments (or cold sleepers) will benefit from a warmer pad with R-values from 5 to 9.
Eat before bed
Your body burns calories to generate heat. Give your body plenty of calories and stay hydrated if you want your best chance of staying warm in the cold. Remember: a sleeping bag only retains the warmth your body creates, it doesn't generate any of its own.
Strip wet layers
It may be tempting to put on every layer you have on cold nights, but overlayering can cause wet or sweaty clothes which can make you colder. Strip down to dry baselayers, then layer up if needed.
Cover your head
You lose significant heat through your head. Cinch your bag's hood, wear a beanie, or both. Same for feet! Clean dry socks (or down booties) target the spots that lose heat fastest.
Wash your bag
Dirt, oils, and moisture flatten down and reduce loft. A bag that's been used 50 nights without a wash could be meaningfully colder than the same bag fresh. See our wash instructions here →.
Store loose, never compressed
Long-term compression in a stuff sack damages the down clusters and reduces loft. Store in the cotton sack that ships with your bag, in a dry place, uncompressed.
Altitude
In addition to the temperature drop usually associated with high-altitude expeditions, elevation can have a huge effect on how effectively your body functions and recovers. At altitude (particularly during rest), breathing rate slows, blood thickens, and both heat and oxygen have a harder time circulating to extremities. Account for a dip in fitness if you'll be consistently above 8,000 ft (2400m).
Tent or Shelter
As simple as it may seem, camping in a tent or other enclosed shelter really is warmer. Shelters can reduce the amount of heat lost through radiant, evaporative, and convective cooling.
Reach Out To Us
Our Seattle staff help people through the sleeping bag decision process every day. We're happy to help! It's a 5-minute conversation that saves you a returned bag.