John Muir once headed for the mountains with bread, tea, and some blankets.
I admire the grit. I respect the disdain for comfort. But I’m also fairly certain Muir would trade those woolens for a modern down bag in a heartbeat. Not because he’d miss luxury, but because down is lighter than wool. Much lighter. The tea, though? That stays. You can’t argue with tea.
Whether you’re hitting the backcountry alone, dragging gear for a family weekend, or walking the Camino, there is a bag for it.
We’ve spent years testing these things. We’ve slept in mud, snow, and heat. We’ve found what works and what doesn’t. This isn’t theory. It’s field tested.
Updated November 2024: Nemo’s Disco 15 now tops the list for side sleepers. We dropped the Marmot that went sold out and the Rab that vanished into obscurity. Prices and links are fresh.
Contributors: Adrienne So and Martin Cizmar helped put this together.
Mountain Hardware Bishop Pass 15
Best for Backpackers
If you want the best bang for your buck, this is it.
The Bishop Pass 15 hits that sweet spot of warmth-to-weight without emptying your wallet. It’s not perfect. Nothing is. But it strikes a compromise most hikers can live with.
It weighs 2 pounds, 5.4 ounces. That’s light enough that you won’t resent hauling it even when July heat makes you wonder why you’re wearing a coat at night.
I slept in this bag for two straight weeks. Nights ranged from a crisp 28 degrees to a sticky 65. At 65? It was torture as a bag.
But then I unzipped it. Used it like a blanket. Suddenly, it wasn’t torture. It was versatility.
The build is solid. 650-fill-power down inside a 20D water-resistant shell. The draft collar is the hero here. Cinch it up and your head stays warm without needing a hat. Most bags leave you freezing from the neck up. This one doesn’t. No cold spots. Just warmth.
The downside? It’s tight.
It’s efficient, sure. It hugs you to keep the heat in. But if you’re a kicker, a kicker in the night, this isn’t your bag. Look elsewhere. The zipper is also… okay. The pull glows, which is nice when you’re fumbling in the dark. It doesn’t snag much. But it doesn’t slide as buttery as others either. Minor gripe. Big performance.
Specs: Rated to 15°F (-9°C). Comfort down to 26°F (-3°C).
REI Siesta Hooded 4
Best for Car Campers
Don’t waste money on a car-camping bag.
You have a car. If things go south, you go back inside. The REI Siesta Hooded 20 gets this. It’s affordable, it’s warm enough, and crucially, it’s rectangular.
Who wants to feel like a mummy when they can just stretch out?
It uses recycled polyester for both the shell and the fill. Despite being synthetic, the lining feels softer than some pricey down options I’ve tried. The 20-degree rating covers most three-season trips.
But here’s the kicker: it has a hood. And zippers.
A full-length one lets you turn it into a quilt if you get hot. A second, partial zipper on the opposite side gives you airflow options. You can even zip two of these together if you’re traveling with someone. A luxury, maybe, but a good one.
Specs: Rated to 20°F (-6°C). Polyester fill.
Zenbivy Bed
Best All-in-One System
Comfort king.
I’ve never slept better in the woods than on the Zenbivy Bed 25. It’s not for climbing Everest in a blizzard. It’s for when you just want a night’s sleep that doesn’t suck.
It’s not a bag. Not really.
It’s a system. A sheet, a hood, and a quilt that you assemble based on the weather. The top sheet sits on your pad. It’s 50-denier polyester. It feels like bed linen. Actually. Like, really good sheets.
You throw the hood (attached to the sheet) and the top quilt over it. For warm nights, leave it loose. Air circates. You breathe. I sleep hot, so I lived in this config.
When it froze? Like it did on the Keweenaw Peninsula last year?
You zip up the footbox. You zip the sides to the sheet. Suddenly, you have a mummy bag. But a comfortable one. You’re cocooned but not crushed.
My only complaint? The pad.
The Zenbivy sells a full set with a pad included. That pad is comfortable. It is also heavy. If you’re car camping, great. If you’re hiking miles? Leave it home. Buy a lighter pad from our other guides. The 25F model I tested is perfect for shoulder seasons, but a 10F exists for the cold-blooded.
If you’re done with tight mummies and don’t plan on surviving sub-zero survival situations, buy this.
Specs: Rated to 25°F (-4°C). 700-fill hydrophobic down.
Sea to Summit Spark 15
Best Ultralight
For those who weigh their food.
Quilts are popular with ultralighters. I mostly hate them. Or at least, I couldn’t find one I liked until now. The Spark 15 is different.
It weighs 1 pound, 9.7 ounces.
It’s the lightest bag on this list. And it packs down smaller than anything else I’ve tested in this temp range. Tiny. Like, shoe-box tiny with the compression sack.
It gives you the freedom of a quilt but seals you in like a bag. Good for fall. Good for through-hiking. Good for saving ounces.
Sea to Summit updated this series. The inner liner went from flimsy to 10D nylon. A modest upgrade, but a welcome one. The outer shell has a PFC-free water repellent. It’s thin. Handle it like it’s made of glass. But honestly? My old one held up fine. We’ve tested Sparks since 2018. Zero failures.
The insulation is 850-fill goose down. Hydrophobic. Zippers are small but smooth.
I’ve used the 15F (formerly 18F) down to 30°F. I woke up sweating. Again, my issue, not the bag’s.
It’s tight. If you need room, look away. At $549, it’s steep. Ultralight always costs money. There’s a Spark Pro line too, with full-length zippers for that quilt-like conversion. Haven’t tested it, but the idea sells itself.
Specs: Rated to 15°F (-6°C). Comfort to 29°F (-2°C).
Nemo Disco 15
Best for Side Sleepers
Let’s be real. Mummy bags are bad for side sleepers.
You try to curl up. The bag fights back. You wake up numb.
“Why does a bag need to hug you like a vice?”
The Nemo Disco 15 gets this.
It has a spoon shape. Extra room in the hips and knees. You roll over. You don’t pop out. You stay in your warmth bubble.
It’s built for 15-degree weather. But it breathes. There are zippered “gills” to vent heat if you’re in the 40s. I kept them closed in the 30s. Wasn’t overheating.
The hood is loose. The draft collar isn’t as aggressive seal-as-tight as traditional bags. But who cares? You’re not fighting for life. You’re trying to sleep.
It uses 650-fill down. It doesn’t pack as small as higher-fill competitors. If you need higher fill power, prepare to pay more. Significantly more. This bag just works for side-sleepers without the quartz-tax.
—Martin Cizmar
Therm-a-Rest Questar
Best for Active Sleepers
I called a sleeping bag a “mummy” bag in front of an 8-year-once.
She looked at me. Deadpan.
“What? Who wants to be a mummy?”
Right. No one.
The mummy cut is for survival, not sleep. But Therm-a-Rest argues for a middle ground. They call it W.A.R.M. fit. With Additional Room For Multiple positions.
The Questar 20 lives up to the name. It’s roomy for a down bag. I pulled my legs up. I rolled. I tossed. I turned. I slept like a baby who hasn’t learned to throw things off the changing table yet.
It uses Nikwax treated down. The shell is 20D polyester. It sheds moisture well, which matters when your tent is smaller than your ego.
The SynergyLink connectors attach the bag to your pad. This stops sliding. This matters for comfort.
At 2 lbs 3 oz, it’s not the lightest. But the comfort rating is 32°F. I used it at 25°F in the Porcupine Mountains. Didn’t break a sweat. There’s also a 32F and a 0F in the line. Haven’t tested them. But if you want to save weight and stay above freezing, the lighter options are worth a look.
Specs: Rated to 20°F (-8°C). Comfort to 32°F (0°C).
REI Co-Op Magma
Best for Shoulder Seasons
No frills. Just warmth.
The Magma 15 is what you grab for early spring or late fall. When the weather can shift from nice to icy without asking permission.
The 15D shell is bluesign-approved and DWR treated. The baffles are stitched through, variably spaced. This keeps the 850-fill down where it belongs. No cold spots.
The hood? Excellent. Stays put.
The zipper? Also excellent. REI put a woven barrier behind it. The down doesn’t get in. The zipper doesn’t jam. It slides. Fully, from foot to collar.
It comes in nine sizes. From Short Narrow to Long Wide. Weighing ranges from 2 lbs to nearly 3. There’s also a 30-degree version if summer is your only season. I haven’t used it. But I recommend it for those warmer months.
Specs: Rated to 15°F [-9°C]. Comfort to 21°F (-6°C).
A Note on Quilts
For the Gram Counters
Quilts rule for those obsessed with ounces.
Why carry a bottom that just gets crushed against the ground? A bag’s lower half serves no insulation purpose once you’re on a pad. Quilts cut that dead weight.
