Best Sleeping Bags for Backpacking in 2020: Ultralight (Lightweight) Bags Reviewed

In anything apart from the warmest weather you’re going to need a sleeping bag to spend a comfortable night outdoors.  Choosing the best sleeping bag for your needs requires some planning.

There are a whole range of factors you’ll need to consider because the range of bags on the market is huge. Picking an unsuitable one could cost you some uncomfortable nights – or even be dangerous.

Our Top Two Sleeping Bag Choices:

1. Top 20 Degree Ultralight Hiking Bag: Teton Sports Trailhead 20F Ultralight Sleeping Bag
2. Top 0 Degree Lightweight Bag: Ledge Sports Zero Degree Ultralight Compact Sleeping Bag

Lightweight/Ultralight Backpacking Sleeping Bag Buyer’s Guide:

The bag that’s right for you is going to depend on many things. This includes the climate you expect to use it in, the seasons you plan to be outdoors, the activities you do and how it works together with your other gear.

You should take the same consideration on any outdoor gear, just like you would for hunting binoculars or walkie-talkies. These all make a difference. A lightweight summer bag won’t keep you warm in a Midwestern winter. At the same time, you can’t just buy the warmest bag available either.

Extra insulation comes with more weight and bulk. There are more trade-offs too, especially for ultra-light backpackers. You can save a lot of weight by opting for a down-filled bag, but down loses most of its insulating ability if it gets damp.

So you might need a bivy bag to make sure it stays dry, and that can add a lot of the weight back on to your load.

Backpackers are the ones who need to pay most attention to their choice of sleeping bag. If you’re in an RV, or driving to your campsite, you can easily carry the extra gear you need to stay warm even with a lightweight sleeping bag.

Air mattresses, blankets, even space heaters can all make sure you don’t wake up shivering in the small hours. For a backpacker it’s different. Bivy bags or liners can add a small amount of insulation but the sleeping bag itself is critical.

So what sort of choices do you have? There are two traditional shapes for sleeping bags – the rectangular variety or the mummy-shaped sort. For backpacking you should usually consider a mummy design. You’ll get a lot more insulation for the same weight and bulk.

You also won’t waste body heat warming up all the extra air trapped inside a rectangular bag. The hood will also do a lot for your comfort. In summer you can leave it loose to get a touch more ventilation.  In the winter it will protect your head, shutting off a major route for heat loss.

Rectangular bags have their good points though. They’re roomier, and you can usually zip a pair together to make a double bag or open them out fully and use them as a quilt.

The Top 3 Sleeping Bag Filling Material Choices:

Next you need to consider the filling material. This can make a huge difference to performance. It’s the filler that holds the inner and outer shells of the bag apart, creating the air gap that gives you insulation.

It needs to be springy, light and durable. It also has to have minimum bulk, so it doesn’t fill the air space you need. There are three alternatives here: Synthetic fiber, down and water-repellent down.

1. Synthetic Fiber Material:

Synthetic Fiber is the cheapest option, so as you’d expect it has its disadvantages. It’s heavier than down and doesn’t pack down as small, so for the same temperature rating you’ll have more weight and bulk. It also isn’t as durable and tends to lose its spring if it stays compressed too long.

To extend the life of a synthetic bag don’t store it in its stuff sack; roll it loosely or, even better, hang it up unrolled.

It isn’t all bad news though. Synthetic fill will retain much of its insulation capacity even when it’s wet, so it’s less vulnerable to the elements than a down bag.

2. Down Feather Filling:

The soft, springy under layer feathers from a goose or duck will cost you more than a synthetic bag.  In the long run it will work out cheaper. Down is a lot more resilient than artificial fibers so your bag will have a longer life. In fact it lasts so long that the filling will probably outlive the shell.

Some companies will take your old bag and transfer the down into a new shell for you. You can store a down bag packed without doing it much harm. Down is also super-light and packs down very small, and that makes it very attractive to backpackers.

The problem with down is that as soon as it gets damp it collapses and loses almost all its power to keep you warm. We’re not quite sure why that is, because it comes from ducks, but it’s a fact. If you opt for a traditional down bag you’re going to have to pay attention to keeping water away from it – including when it’s in your pack.

3. Water-Repellent Down :

Water Repellent down is becoming increasingly popular. This consists of natural down that’s been chemically treated to repel water, which prevents it collapsing when it gets wet.

These bags are the most expensive but combine the best features of both synthetic and down.

If you want a light and durable bag that will stand up to long use and wet weather, and you don’t mind paying a premium of about $20-$30 for it, this is the best option.

Choosing the Right Thermal Rating:

The final thing to consider is your bag’s thermal rating. Until a few years ago this was a lottery, with some manufacturers using vague “season” ratings.  This included confusingly named five-season bags – and others assigning a temperature rating based on their own testing and opinions.

Recently there’s been a quiet revolution though, as the more standardized European Norm (EN) system has been adopted. Most quality bags are now EN-rated, making it much easier to find the right one for you and the conditions you’ll be using it in.

An EN-rated bag has three temperature ratings; the first two are the ones you should pay the most attention to. They also correspond to genders, because women tend to sleep colder than men.  As a result, they will need a more insulated bag for the same outside temperature.

The first number is the “comfort” rating.  This is the lowest temperature where the average woman will stay warm in the bag. The second is the “lower limit” and, of course, that’s the lowest temperature where the average man will stay warm. For most people, as long as you use the bag at a temperature above those figures you should be able to get a comfortable night’s sleep.

The third number is the bag’s “extreme” rating. This is the lowest temperature at which it will keep the average woman alive. If you’re using a bag anywhere close to its extreme rating don’t expect to sleep much, if at all.

You’ll definitely feel the cold, but it should be enough to stave off hypothermia. Don’t ever decide to economize based on this rating – if you plan to be out in temperatures of, say, 20°F get a bag with the appropriate comfort or lower limit. Picking one with a 20°F extreme limit will result in a lot of very unpleasant nights.

There are some other things you can look for in a bag. A box foot will make for a roomier bottom end, and can prevent you getting tangled if you tend to move around a lot in your sleep. Some bags come in a choice of lengths and in male or female fits.

Don’t go for an excessive length in the hope it will be more comfortable – you’ll just be carrying more weight all day, and keeping more air warm all night.

Anyway, let’s look at some of the top backpacking bags. We’ve split them into two categories – ones rated down to 20°F, which are ideal for early spring through to late fall, and 0°F rated bags that should cope with most winter weather.

Four Awesome 20°F Lightweight Sleeping Bags for Hiking:

1. Teton Sports Trailhead Ultralight:

Squarely aimed at lightweight backpackers, this bag weighs in at a touch under three pounds. It’s a mummy style, filled with synthetic PolarLite, and it has a really comfortable brushed lining.

It also has a boxed foot, which makes a real difference to comfort, and a drawstring hood.

This is another bag that’s marginal at 20°F but you’ll be perfectly fine down to freezing, and adding a light fleece will ensure you’re comfortable at the stated limit. Its weight makes this a very attractive option for lightweight camping on a budget – it’s reasonably priced – and it has some neat features too.

There are exterior loops for hanging or fastening to your mat, plus a zippered pocket to hold your flashlight or valuables.

2. Kelty Ignite Dri-Down Lightweight:

Kelty’s Ignite is a high performance mummy style bag that uses a water-repellent 600 fill Dri-Down filling. It’s very well put together and a lot of attention has gone into eliminating possible cold spots – box baffles avoid through stitching and the long anti-snag zip has a generous baffle. The hood has a captive cord so you can easily adjust it with one hand.

Inside you’ll find attachment loops for a liner, which you’ll really appreciate if you’ve ever had a loose liner wrapped tightly round your legs. Outside are more loops to fasten the bag to a sleeping mat, so there’s no risk of slipping off your mat during the night, plus a hanging loop at the foot.

There’s also a compact stuff sack. This is a very light bag at under three pounds; it’s available in regular, long (up to 6’6”) and women’s sizes. The Ignite isn’t cheap – but it’s excellent quality and as with most outdoor products, you get what you pay for.

3. Suisse Sport Alpine Ultralight:

The Alpine is a mummy bag, this time filled with Hollowblend synthetic fiber. It’s constructed with double layer offset filling, so there isn’t any stitching that runs right through – and that means there aren’t any cold spots, either.

It’s a cheaper alternative to box baffles and it’s just as effective, but slightly heavier. On the other hand the result is a good warm bag at a very affordable price – and you get a lot of features for your money.

Among those features are a drawstring hood, a full baffle on the zip and a soft polyester lining. It’s quite generously sized and suits anyone up to about 6’2”.

Weight comes in at almost exactly 5 pounds including the supplied compression sack. This is a good performer at a very attractive price and makes an excellent  choice for backpackers, hikers, hunters or anyone that needs a well insulated mummy bag on a budget.

4. Therm-a-Rest Hyperion 20°F UL Sleeping Bag :

Here’s a premium 3-season sleeping sack that will keep you toasty all night long and will pack down real small to fit into your backpack while on the trail. At just 22 ounces, the Therm-a-Rest Hyperion is an ultralight down sleeping bag for backpackers like you’ve never seen before.

It is made of 900-fill Nikwax Hydrophobic Down which maintains loft 60 times longer than a regular down sleeping bag when moist. The bag comes with SynergyLink connectors which prevents you from falling from the pad while getting those much-needed Zzzs.

There are three sizes available – small (1 lb 3 oz), regular (1 lb 4 oz) and tall (1 lb 6 oz). All sizes come with a compression sack and a regular storage sack and they pack down ultra small (6 x 8 inches for the tall size). What’s more, because the bag has Responsible Down Standard Certification, it means that the birds used in its making were treated humanely.

5. Coleman North Rim Lightweight Sleeping Bag:

The North Rim is a standard mummy bag that gives you a lot of quality and features for the asking price.

The cover is ripstop polyester and the liner, also polyester, is a softer and more comfortable grade. In between them is 60 ounces of Coletherm synthetic fill in an offset quilting pattern.

As well as zipper and shoulder baffles it has a box foot, making it very comfortable.

It comes with a standard stuff sack so consider getting a compression one to reduce the space it needs. Overall the packed bag weighs 6 pounds – reasonable for this sort of performance.  At 3.75 pounds, this sleeping bag is light and durable.

Three Great 0°F Lightweight/Ultralight Bags For Hiking:

1. Ledge Sports FeatherLite Ultralight Sleeping Bag:

The FeatherLite is a very different bag from the Celsius. It’s mummy shaped and filled with Hibernate Extreme continuous filament fiber.

This is one of the more effective synthetic fillers we’ve seen and gives amazing insulation at a very low weight – packed in its compression sack this bag weighs just 3.8 pounds, which is excellent for a 0°F item.

In fact we think 0°F might be slightly optimistic for this bag, but only by a few degrees, and at this weight it’s one of the better performers.

It also has a good-sized internal pocket and a hood that can be pulled closed to a very small aperture. It’s also in a great price range, which makes it a real bargain.

2. ALPS Lightweight Mountaineering Crescent:

This is a polyester mummy-style bag with a double-layer construction to eliminate cold spots. It’s very warm, thanks to a well-designed hood and full length zipper baffle, but at 6 pounds it’s not as light as the others on our list, but it’s serviceable.

It comes with a standard stuff sack, so you may want to add a compression model to take up less space in your pack.

The Crescent is a simple and conventional bag, but a very effective one and it’s also well priced. It’s available in three sizes – regular, long and wide – so there’s an option that will fit just about anyone.

3. Wenzel Windy Pass Ultralight Sleeping Bag:

Another all-synthetic mummy design, the Windy Pass is a solid bag that still gives decent performance.

It’s quite basic but does have the most important features for warmth – large, three-inch shoulder and zipper baffles.

The filler is Omega III synthetic, which is reasonably lightweight, so the Wenzel tips the scales at around 4.5 pounds.

Like almost all mid-range 0°F bags it uses offset construction to avoid cold spots, and it’s pretty effective. It’s not the warmest of bags at zero degrees, but unless you’re a very cold sleeper it should easily be warm enough for a comfortable night.

Wrapping Up & Final Thoughts:

Any of these bags should keep you warm enough from spring through to fall, and the 0°F models will be fine in most winter weather, too. The balance definitely leans towards the mummy style for backpackers.

These may not be as roomy as the square sleeping bag you had as a kid, but they will keep you just as warm for less weight and bulk. That’s even more important as you start to add more insulation – the -25°F Teton has plenty of space, but it’s not something you’d want to carry all day if you could avoid it.

If you are looking for some great Camping Sleeping Bags to go in your base camping tent that are heavier in nature, check our our camping sleeping bag reviews by clicking here.  If you’re planning extended hiking you should always opt for a mummy design.

Special mention goes to the outstanding Kelty Ignite in the 20°F class – the Dri-Down filling is really something special – and either the FeatherLite or North Rim for winter weather.