The Best Sleeping Bag Liners in 2024 (and Why You Need One)

It’s one of life’s loveliest truisms that the best things come in small packages. We’re thinking Nutella dipsticks, tea, Tyrion Lannister, Tootsie Rolls, Ringo Starr and Cadbury’s Cream Eggs, for example. For our money, a very worthy addition to that list is the sleeping bag liner. These tiny, marvellous little additions to your outdoor kit are often overlooked by the no-frills adventurer, but to any marginally hygiene-conscious and practical backpacker or outdoorsperson, they are a frill well worth having.

At Cool of the Wild, we like to think of them as a night-in-the-outdoors optimiser and backpacker’s best friend. Excuse our excessive enthusiasm, but these little wonders of the camping world are so damn useful that we’re frankly upset that some unhappy campers might not be using them. Here’s a sneaky preview of what you might be missing out on:

Disclaimer: We use affiliate links and may receive a small commission on purchases.

But before we get down to our review of the best sleeping bag liner for 2024, let’s take a quick look at why they should feature in the backpack of every sleeping bag user, wild camper, traveler, backpacker and overnight adventurer…

Sleeping bag liners: why you need one

Ever been a little bit disappointed that your 40 degree sleeping bag starts feeling a bit chilly even at 45? Or that after a few nights in the wild it seems to have acquired scents hitherto unknown to your nauseated nostrils? How about rocked up at a mountain hut or hostel and discovered the sheets you’ll be sleeping in have been unmolested by the waters of a washing machine since around your date of birth? In that case, or even if you just fancy a bit of a comfort booster while catching your nightly winks, a sleeping bag liner is definitely going to be a welcome and worthwhile addition to your kit.

Yep, for an extra few hundred grams of weight and a size comparable to a pair of socks, all of the above bother could be easily avoided. Here’s how:

Warmth

Sleeping bag liners act much in the same way as your layering system does in clothing, forming an added buffer between your body and the ambient air, creating a layer or pockets of warm air on either side. This can enhance the low temperature rating of you sleeping bag by up to 5 degrees.

Hygiene

We outdoorspeople can occasionally be a tad lax on the hygiene front. Where, after all, is one supposed to do one’s bathing when the temperature of the only water in one’s vicinity is half a degree short of Arctic? Even if we’re particularly fussy about bodily cleanliness when in the outdoors, sleeping bags tend to concentrate and collect odor like no other material known to man. Liners counter that problem by offering a washable ‘barrier’ and so can also extend the life of your sleeping bag by minimising washing and protecting the materials from, well, you!

Coolness

If you happen to be summer camping when nighttime temperatures are a little too toasty for your sleeping bag but a little too cool for sleeping in the open air, your liner can give you that little bit of warmth and comfort needed to get in some comfy kip.

Protection

If you’re trekking in the Alps or elsewhere across Europe, the chances are the mountain huts you’re sleeping in will demand that you have a sleeping bag liner. You’ll appreciate their insistence when you see your bed for the night, trust us! In an effort to save on water and a limited electricity supply, the washing of bedsheets in these places can be a sort of once-in-a-decade event, if you’re lucky. Having a liner will spare you the affront of that decade’s accumulated grime and ‘musk’. The same goes if you’re staying in hostels – while they’re unlikely to stipulate that you use a liner, in our experience there are sure to be a few occasions when it’s highly advisable!

Types of sleeping bag liner

Silk

If you’re serious about your sleeping bag liner and don’t mind spending a little more to get the best, silk is the way to go. Not only does silk feel oh-so-good against the skin and require very infrequent washing, it packs down to an incredibly small size (a tennis ball is a good comparison) and can weigh as little as 200g.

Cotton and polycotton

Though the ‘cheap’ option, cotton and polycotton liners usually offer a very comfy, cosy feel and can even boost the warmth of your sleeping bag by a degree or two more than silk options. They don’t squeeze down to quite so tiny a bundle as silk liners and usually weigh a fraction more, but are normally a little less prone to ripping, a good deal cheaper, and can be thrown in the washing machine with the rest of your smellies without damaging the fabric.

What to look for in a sleeping bag liner

01Weight

Whichever sleeping bag liner you opt to buy, the chances are it won’t add more than a few hundred grams of weight to your pack. That said, every little bit counts, and if you can shave off a few grams, all the better! If the liner you are considering buying happens to be extremely light, be sure to check that those extra grams haven’t been shaved off at the expense of length or other features. On the other hand, if the liner seems unreasonably heavy, it might just feature a few more much-needed centimetres or added insulation and so be worth the extra weight.

02Shape

Sleeping bag liners come in a variety of shapes and sizes to accommodate the needs of every adventurer:

• Standard: Rectangular shaped liner with more room at your feet than mummy liners
• Long: As above but adapted for taller humans
• Mummy: Wider at the shoulders and narrower at the feet, these liners are super-snug and offer a better fit for mummy-style sleeping bags. Many models also come with a hood for that extra cocoon-like feel
• Double-width version: For those travelling in two or of an excessively claustrophobic disposition
• Traveller: Usually rectangular in shape, a fraction longer than standard liners and with a built-in pillow extension in case you happen to be staying in a hut, hostel, bothy or hotel where concern over hygiene is not especially in evidence

03Convenience

This is all about machine-washability. While silk liners are usually hands-down winners in terms of quality and packability, to keep them in good nick you’ll have to wash them by hand. Polycotton and microfiber liners, however, can all be chucked in the machine with the rest of your gear.

04Value for money

Having already forked out a hefty amount for your sleeping bag, you want to make sure you’re lining it with something that will offer the best in terms of the price to performance ratio. If a liner is pricey, check that it’s of good quality and has the blessing of happy customers in user reviews. Likewise, if you find a liner that’s very cheap, try to find what it’s missing that other liners have (double stitching, hood, antibacterial properties and a small pack size, for example).

The 11 best sleeping bag liners for all your outdoor adventures

Got all that? Good…now, let’s get down to the nitty-gritty with Cool of the Wild’s selection of the best sleeping bag liner for 2024!

Big Agnes Fleece Sleeping Bag Liner

The Big Agnes Fleece Sleeping Bag Liner is designed to be used on its own on warm nights or boost the temperature in your regular sleeping bag. This cosy fleece liner has a reversible design, allowing it to fit inside right or left zipper sleeping bags. Hooks at the head and foot of the liner can attach to the sleeping bag to keep the liner in place. The top opens to a generous 42” so you can slip in and out easily too. Plus, a simple drawstring hood lets you snuggle in and keep cold drafts out. This Big Agnes sleeping bag liner is made with Polartec recycled microfleece which can add 5-10 degrees of warmth to your sleeping bag’s temperature rating.

Find the latest price on:
Amazon | evo

Cocoon Coolmax Mummy Liner

It ain’t silk, but the CoolMax polyester blend used in the Cocoon Coolmax sleeping bag liner is just about the next best thing, if not on a par with with its pricier silk competitors in all but packability. The CoolMax boasts great wicking capabilities, breathability and can add up to 8.4 degrees of warmth to your sleeping bag. While pricier than most other non-silk options, this is a dead-cert contender for the title of best sleeping bag liner for warmth.

Find the latest price on:
Amazon

Sea to Summit Adaptor CoolMax

The S2S Adaptor is a super-comfy, high-performing liner that works well as a stand-alone cover for sticky summer nights or a nice little temperature booster for your regular sleeping bag. Like the Cocoon Coolmax it features great breathability and moisture wicking, but comes in a fraction lighter and with a very handy footbox for added room and less toe-snagging when tossing and turning.

Find the latest price on:
Sea to Summit | REI

Dimples Excel Sleeping Bag Liner

In the Dimples Excel, we have a serious contender for the title of best budget sleeping bag liner. This very light, roomy little satin number, however, isn’t just cheap but measures in at a very spacious 86 x 41 inches, weighs just over 8oz and has a very small pack size. Compared to the Coolmax or silk options in our review it’s a bit short on wicking and breathability, but if the prices of these liners are a bit rich for you, the Dimples Excel is a very adequate alternative.

Find the latest price on:
Amazon

Sea To Summit Reactor Thermolite

While pricey, the S2S Reactor Thermolite claims to boost your sleeping bag’s temperature rating by up to 15 degrees Fahrenheit – a boon perhaps worth splashing out on and which makes it a real contender for the best insulated sleeping bag liner out there. In addition to its warmth-improving potential, the Reactor packs down to a tiny 3 x 5 inches, weighs only 9oz and is fairly long at 210cm. Compared to other high-end liners, the Reactor holds its own. It’s shorter than the Rab silk liner but also cheaper, and is longer than the similarly priced Coolmax, so a better option for taller sleepers thanks to an extra 10cm from top to toe.

Find the latest price on:
Sea to Summit | Amazon | REI

ALPS Mountaineering MicroFiber Mummy

Although a tad narrow in the foot area and slightly heavier than most items in our review, ALPS MicroFiber Mummy boasts a super-cosy, comfortable feel and price-wise occupies the middle ground between high-end silk or CoolMax options and budget options such as the Dimples Excel and WILD-WIND liners. Packing down to a very slight 3.5 x 6.5 inches and offering a slightly more substantial layer than other super-thin liners, this is a decent option for those seeking a well-made mummy-style bag minus the hefty price-tag.

Find the latest price on:
Amazon | Backcountry

Sea to Summit Silk & Cotton Travel Liner

Along with the other silk liners (below), the Sea to Summit Silk & Cotton Travel Liner is super lightweight and packable, making it an excellent choice for backpacking. The simple design of the rectangular version is similar to the Rab liner which helps to keep the weight low. And although it doesn’t have the luxurious feel of the pure silk options, the blend with cotton is actually very appealing to keep things cool and smooth on the skin in hot conditions.

The silk blended with cotton keeps the price down compared with the pure silk options; the perfect compromise for those wanting some of the properties of silk but not wanting to break the bank! The liner also comes with a zippered bag which compresses down impressively small considering its cotton content.

Like the pure silk options, this lightweight sleeping bag liner is best used in warm conditions and only adds a little extra warmth to a sleeping bag in cooler conditions.

Find the latest price at:
Sea to Summit USA | Sea to Summit UK

Rab Silk Sleeping Bag Liner

If you happen to be a relatively tall human or just fancy a bit of extra length for convenience’s sake, the Rab Silk Sleeping Bag Liner could well be your bag. Measuring a mighty 89 inches (225cm) in length, this beast boasts a minimum of 5cm more lengthwise than any of its competitors in our review. Although this is a pricey option, the pillow insert and added length make it potentially the best sleeping bag liner for backpacking out there. The only downside is the price…

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Cotswold Outdoor | Backcountry

Western Mountaineering Tioga Silk Liner

For an incredibly lightweight sleeping companion, look no further than the Western Mountaineering Tioga Silk Liner. Weighing in at an absolutely featherweight 3.65oz (103 grams), this is the lightest liner in our review and ideal for long-distance adventures where weight is a priority. While it won’t add as much warmth as many other liners and is a touch narrow around the foot area, the WM Tioga is ideal for those keen to keep things ultra-light and more concerned with hygiene, bug-protection and weight than additional warmth.

Find the latest price on:
Backcountry

Sea To Summit Premium Silk Travel Liner

The rather handsome price of the S2S Premium Silk Travel Liner poses a fairly frightful first impression, but the rest of the details might just convince you of its value for money. This incredibly well-made liner features an integrated hood, a tiny pack size, double-stitching, stretchy side panels and weighs in at only 4.6oz. Perhaps the greatest feature, however, is that it defies the two usual drawbacks of silk liners (i.e. they’re easy to rip and require handwashing) in that it’s made of ripstop silk and is machine washable…nice! Together with the integrated hood, these features make this little beauty one of the best backpacking liners out there. In a head-to-head with the Rab liner, the S2S Premium offers less lengthwise but added convenience in the form of the integrated hood, stretchy side panels for ease of entry/exit and machine washability.

Find the latest price on:
Sea to Summit | Amazon | REI

WILD-WIND Backpacking Sleeping Bag Liner

If you happen to be looking for a very cheap but also very cheerful sleeping bag liner, the WILD-WIND Backpacking Liner might just be your best option. While not the most spacious budget liner on our list, it comprises many of the more desirable features of pricier liners without the undesirable price-tag: a side opening, synthetic silk materials, machine washability and a decent temperature boost for chillier nights in the wild. Compared to other budget models such as the Bundle Monster and the Dimples Excel, the Wild Wind is a lighter option but a great deal shorter than the Dimples Excel and lacking the combination zip featured in the Bundle Monster.

Find the latest price on:
Amazon

Bundle Monster Microfiber Fleece Liner

Our final budget option, the Bundle Monster Microfiber Fleece Liner, isn’t much of a ‘monster’ size-wise, but does have a very cosy, soft feel and a side zip that can be attached to another Bundle Monster to make a two-person liner. While this liner is fairly heavy and not as breathable as other microfiber or silk options, it offers decent value for money and is ideal if you are a backpacking couple. Compared to the other budget options in our review it’s quite a bit heavier and shorter, but might just win your favour on account of that handy, zip-together combination feature.

Find the latest price on:
Amazon

Keeping things clean and comfy when out in the wild or backpacking between hostels can be a touch testy. For the unsuspecting and under-prepared adventurer there awaits a host of potentially nasty and/or noxious surprises: stinky sheets and sleeping bags, sweaty summer slumbers and sleeping bag temperature ratings that feel just a little too optimistic. If you want to ensure your adventures are as comfortable as possible and your sleeping bag is a companion for life (as opposed to a potential health hazard after a few uses!), grab yourself a liner! We’re sure one of the above selection will serve you well, keeping your sleeping bag stink-free, a few degrees warmer and thwarting any invaders of the insect or bacterial variety when getting your snooze on!

Happy adventures, people!

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