Best lightweight sleeping bag 2023: Quick links
00. Top 3↴
01. Best overall: Rab Neutrino 400
02. Best premium: Rab Mythic Ultra 180
03. Best budget: Decathlon Forclaz MT900
04. Best mid-range: Robens Icefall Pro 300
05. Best for warmth: Thermarest Hyperion 32UL
06. Best 3-season: Sea to Summit Spark SpIII
07. Best for summer: Alpkit PipeDream 200
08. Best for bikepacking: Vango Ultralite Pro 100
For backpackers, bikepackers and fastpackers, finding the best lightweight sleeping bag is a must. When carrying all your gear on your back, the bulk and weight of a sleeping bag are crucial concerns that need to be carefully balanced with comfort and warmth. You'll find plenty of lightweight sleeping bags for any budget and occasion in this list.
Low-weight and reduced-bulk bags are usually designed for 2- or 3-season use, so most bags featured in this guide are intended for use from spring to autumn. Check our best sleeping bag roundup if you're after warmer options. Whichever sleeping bag you choose, pair it with one of the best camping mats for a great night's sleep. Finally, head to our best backpacking tent guide for similarly light and compact outdoor shelter options.
We're approaching the tail-end of the camping season, but the weather seems to be holding up nicely, meaning it's still possible to enjoy a pleasant night under the stars using only a lightweight sleeping bag (and a tent). If you're planning on buying a sleeping bag now, look for the 3-season models that can keep you warm even if the temperature falls slightly by the morning.
The Top 3
Best lightweight sleeping bag overall
The Rab Neutrino 400's near-perfect weight-to-warmth ratio is achieved by ingenious design trickery and solid quality filling – 800FP European Goose Down with Nikwax Fluorocarbon-Free Hydrophobic Finish. For an all-rounder bag that won't weigh you down but will handle cold reasonably well, this is a winner.
Best premium lightweight sleeping bag
Rab's Mythic Ultra 180, the lightest in the range, clocks in at 400g. It's still limit-rated to zero degrees, too, which means it'll handle a wide range of outdoor excitement and still keep you happy. It's also super high-tech and packs down incredibly small. If you can afford it, it's a superb choice!
Best budget lightweight sleeping bag
If you're on a tight budget, check out the Forclaz MT900. The folk at Decathlon have been busy here, knocking out a 700g mummy sleeping bag for a fraction of the price of the top performers in this class. There's also a full-length zip, making this a very flexible late spring/summer/autumn bag, indeed.
Best lightweight sleeping bags to buy right now
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The Rab Neutrino 400 Down Sleeping Bag will sound familiar to many an outdoorsy type, for the very good reason that Rab Neutrino down jackets and sleeping bags have been around for several decades. This model does the heritage proud, weighing in at a decent lightweight 775g, with a comfort rating of -7C / 20F.
We found this the perfect companion for all sorts of chillier adventures where weight is a factor. The weight-to-warmth ratio is partly achieved by ingenious design trickery (chevron baffle design, trapezoidal box wall construction) and solid quality filling – 800FP European Goose Down with Nikwax Fluorocarbon-Free Hydrophobic Finish. For an all-rounder bag that won't weigh you down but will handle cold reasonably well, this is a winner.
Read our full Rab Neutrino 400 sleeping bag review.
We think the best lightweight sleeping bag in the premium category right now is the Rab Mythic Ultra 180. Rab has a lot of good history building excellent sleeping bags, and this featherlight model is both highly technical and really, really light. There are various weights in the range, so you can pick the best version for your lifestyle, but the lightest, the 180, clocks in at 400g. Yeah, 400 – less than four Mars bars. It's still limit-rated to zero degrees too, which means it'll handle a wide range of outdoor excitement and still keep you happy.
Part of this achievement is down to top-notch materials and part to technical innovation. Rab has knocked up a world-first – Thermo Ionic Lining Technology (TILT). This impressive-sounding acronym is actually a coating of Titanium bonded to the fibres, enabling them to reflect heat back at you, boosting warmth. It's a canny trick and, most importantly, doesn't add much in the weight department.
If you're on a tight budget, check out the Decathlon Forclaz MT900. The folk at Decathlon have been busy here, knocking out a 700g mummy sleeping bag for a fraction of the price of the top performers in this class. There's also a full-length zip, making this a very flexible late spring/summer/autumn bag, indeed.
However, the temperature rating is where this falls down, considerably less warm than some of the competition. The key reason for that is the fill material, mixing in much cheaper duck feathers to bring costs down, as well as a Polyamide Shell outer. Interestingly, the MT900 is a successor to the older Trek 900, but with a higher percentage of Duck Down, and all of it RDS certified - both considerable improvements. Price is still laughably low for this spec and weight, too, making it an excellent contender for warmer camping. Overall: good design, good lightness, good price, budget fill materials – well worth a balanced look.
While we're not sold on the colour, the Robens Icefall Pro 300 offers some strong value for money in the lightweight sleeping bag arena, as well as being synthetic filled. This means it'll handle wet conditions much better than a down bag, still keeping you warm in soggier surroundings.
Designed for warmer weather camping only, this bag boasts plenty of handy design features, including a mummy shape and narrow foot box to keep heat trapped in around the legs, a generous length of 195cm, and a synthetic filling that effectively mimics the heating properties of down feathers. However, the standout is the central zip, which is intuitive and feels much easier to use than a traditional side positioning (one irritation is that the zip tends to catch on the surrounding fabric, so you'll need to be careful when opening and closing it).
Read our full Robens Icefall Pro 300 sleeping bag review.
Best for warmth
The Thermarest Hyperion 32UL boasts an enormous 900 fill GooseNikwax Hydrophobic Down to keep you warm down to a comfort limit of zero degrees, which is impressive considering how light this is. It also packs down to around the size of a 1L water bottle. The Nikwax treatment on the down itself staves off some of the worst effects of damp, with the treatment staying drier and, according to Nikwax, maintaining loft 60 times longer than untreated down.
A thermally-efficient box baffled construction and zoned fill (70% on the top and sides with 30% on the back) keeps the insulation around your core for maximum warmth and minimum weight, and finally the down filling is Responsible Down Standard Certified. It's not cheap, but it is one of the best lightweight sleeping bags you can buy, and after a long day carrying it, you won’t regret spending the pounds (or dollars) to save those grams.
The Sea to Summit Spark SpIII Sleeping Bag lofts beautifully and luxuriously in double-quick time, and we had no issues sleeping happily in low-single-figure temps. The proper zip means that venting is easy, and essentially the whole experience is the same as a much heavier ‘normal’ sleeping bag, just with half the weight to tote around.
That weight saving is really the heart and soul here - sure, there are warmer bags, and they weigh at least double this (and plenty more). However, if you’re carrying the Spark SpIII Sleeping Bag over long distances, or engaged in long, off-season days out that might culminate in a hut or bothy, that lack of weight will power you all day long, and you’ll still get a comfy bed at the end of it.
The Sea to Summit Spark SpIII Sleeping Bag might be complete overkill for car campers and occasional outdoors venturers, but if you’re in the market for a technical, easily-carried but warm sleeping bag, this is absolutely one to take a look at - just don’t let the crampons get near it.
Read our full Sea to Summit Spark SpIII Sleeping Bag review.
Best for summer
If your budget is tight, check out the Alpkit PipeDream 200. While the higher temperature rating means this one is strictly for summer-weather trips, it offers a strong warmth-to-weight ratio for a very reasonable price. A filling of water-resistant down traps in heat quickly, and the bag packs down to the size of a small loaf of bread for easy transportation. While it's nice and soft against the skin, this is a barely-there bag, so don't expect snuggliness.
Read our full Alpkit PipeDream 200 review.
Best for bikepacking
Whether you take into account the budget price tag or you don't, the Vango Ultralite Pro 100 is an impressive sleeping bag. The Thermal Reverb system of reflective aluminised lining is designed to bounce your own body heat back to you, and the Polair Active outer fabric remains soft and warm to the touch. At 900g, it’s not feather-lite, but it’s still compact and comfortable to carry when backpacking and hiking. Better still, it comes recommended by both the DofE and The Scout Association and has an extremely reasonable price tag too.
How we test the best lightweight sleeping bags
To put together this ranking, wherever possible, we call the lightweight sleeping bag in and test it out overnight to see how it performs. We'll look at how effectively it keeps us warm, but also how functional it is as a design – is it ergonomically shaped? Can we get in and out of it easily, and does it pack up without too much hassle? Are there any extra design features, like tech pockets, worth considering? Does it feel well-made and robust?
Because this particular guide is all about small and light bags, we'll look at the specs for the bag, how much it weighs compared to its packed size, and how that matches up against competitors' efforts. Here, we'll also factor in how much it costs before deciding where the bag should sit in the ranking.
Info from the brand about how the sleeping bag has been produced, and any notable technologies also feed into our decision-making, along with our knowledge about the brand, its reputation, and our experience with its products so far. Finally, we look at what other reviewers have said to make sure we're not missing anything big.
In the cases where we haven't been able to get hold of a sleeping bag but feel it's worthy of inclusion, we research what other customers and reviewers have said and combine that with our knowledge of the market to put together an informed blurb for you to base your decision off. Find out more about how we test at T3 here.
How to choose the best lightweight sleeping bag for you
There are a few things to know before you make your purchase. Sleeping bags usually state an EN rating, which is the European standard EN13537. EN13537 uses a thermal manikin test that produces four temperature results: upper limit, comfort, lower limit/transition, and extreme. Of these four ratings, ’comfort’ and ’lower limit/transition’ are the most helpful and are what most people look at when buying a sleeping bag. It's also worth bearing in mind that the 'extreme' ratings are exactly that - they're right on the edge where the bag stops working and you go into hypothermia - not a fun place to be.
If you get colder faster than the average person, look at sleeping bags with a higher lower limit. Remember too that real-world variables can have an impact on the performance of a sleeping bag, so these ranges are just a guideline.
Even in the summer heat temperatures can drop at night, and even more so as you climb above sea level (approximately 1 degree less for every 100m), so single-figure EN ratings are a good choice even for a light UK summer sleeping bag.
Unfortunately, while technological advancements mean that most hardware is getting lighter and lighter, there are still limits to what you can do, and nowhere more acute than in sleeping bags. Lighter materials shave off those grams, but lose lots of durability. Elsewhere, DWR coatings and treatments might add vital damp-proofing, but also add in a few grams themselves – there's literally no escape from the scales.
Down filling offers the lightest and warmest potential, but is pretty useless in damp conditions, while artificial fibres tend to be heavier and bulkier, but much happier in soggy UK conditions.