Reviews You Can Rely On

The 5 Best Ultralight Backpacks

We tested ultralight backpacks from Gossamer Gear, ULA, Hyperlite, Mountainsmith, and more to find the best pack for your needs
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Best Ultralight Backpack
Credit: Justin Simoni
Tuesday July 18, 2023

Ready to join the ultralight revolution? Over the past 9 years, our thru-hiking experts have tested 40+ of the best ultralight backpacks around. In this latest iteration, we bring you the top 16 ultralight backpacks on the market. We've slogged along the John Muir Trail, hiked around Southern France's Haute Alpes, and traversed miles of talus in Argentine Patagonia to put these packs to the test. We logged hundreds of trail miles to assess performance, subjecting each one to our rigorous testing metrics, including weight-to-volume ratio, carrying comfort, adjustability, and features. Each year, the ultralight world grows and becomes increasingly competitive. This review highlights budget-friendly models and our top-ranked packs, as well as niche products.

If you're looking to shave a few ounces (or pounds) from your pack, check out our other reviews for the best in ultralight gear. If you're willing to carry a little extra weight for more comfort, larger carrying capacity, and extra organizational features, consider one of the best backpacking backpacks or best women's backpacking backpacks from our reviews.

Editor's Note: We updated our ultralight backpack review on July 18, 2023, to add new and updated models from Osprey, Hyperlite, ULA, Mountain Laurel Designs, Durston, and more.

Top 16 Product Ratings

Displaying 1 - 5 of 16
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Awards Editors' Choice Award Best Buy Award Top Pick Award Top Pick Award  
Price $285 List$255 ListCheck Price at Backcountry
Compare at 3 sellers
$389.00 at Backcountry
Compare at 2 sellers
$260 List
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74
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Pros Abrasion-resistant Robic nylon, comfortable, well-designed pockets, carries both light and heavy loads wellLightweight, carries light and medium loads well, adaptable, perfect feature set, more durable than mostSensational comfort and back breathability, tons of organizational pockets, perfect for those getting into the ultralight lifestyleDurable, simple design, lots of external attachment optionsCarries both light and heavier loads in comfort, large side pockets, very durable construction
Cons Large capacity makes it less versatileA little small for a bear canisterHeavier than other ultralight packs, mesh back may have durability issuesExpensive, lacks features, few external pocketsRelatively heavy, delicate carbon frame rods
Bottom Line This pack wowed us with its perfect set of features, comfortable design, and impressively large carrying capacityDelivers a perfect set of features, plenty of pockets, comfortable straps, and carries well, all at an affordable priceAn excellent pack for those who want to move up from a conventional backpack, but don't want to lose out on creature comfortsBuilt for serious adventures with lots of external attachment points with very durable constructionOne of our favorite packs with its comfortable waist belt, large side pockets, and a volume that is just right for ultralight backpacking
Rating Categories Gossamer Gear Marip... Gossamer Gear Goril... Osprey Exos Pro 55 Hyperlite Mountain... Adventure Equipment...
Comfort (40%)
10.0
10.0
9.0
8.0
8.0
Ease of Use (25%)
10.0
9.0
9.0
8.0
7.0
Weight-to-Volume Ratio (20%)
8.0
5.0
5.0
5.0
7.0
Adjustability (15%)
8.0
8.0
7.0
8.0
7.0
Specs Gossamer Gear Marip... Gossamer Gear Goril... Osprey Exos Pro 55 Hyperlite Mountain... Adventure Equipment...
Measured weight 32.6 oz 31.1 oz 33.2 oz 31.5 oz 31.4 oz
Weight per liter (full pack) 0.54 oz/L 0.62 oz/L 0.60 oz/L 0.57 oz/L 0.50 oz/L
Advertised volume 60 L 50 L 55 L 55 L 63 L
Stripped weight 18.0 oz 17.2 oz 30.4 oz 31.5 oz 20.4 oz
Measured volume (main compartment) 42 L 39 L 33 L 35 L 41 L
Main pack pockets 5 4 3 None 3
Lid (aka brain) Yes Yes Yes No No
Hydration compatible Yes Yes Yes No Yes
Single side pocket 700ml Smartwater capacity 5 3 5 N/A N/A
Hip belt pockets 2 2 2 2 2
Single hip belt pocket capacity 5 Clif Bars 5 Clif Bars 4 Clif Bars 6 Clif Bars 8 Clif Bars
Able to strip off frame and hip belt Yes Yes No No Yes
Mix & match hip belt sizes M
(S & L sold separately)
M
(S & L sold separately)
No No XS, S, M, L, XL, XXL
Shoulder strap pockets No No No No No
Whistle on sternum strap Yes Yes Yes Yes No
BearVault BV500 compatibility Good Ok Good Ok Ok
Sizes available S, M, L S, M, L S/M, L/XL S, M, L, Tall S, M, L, XL
Frame type SitLight foam pad / removable stay SitLight foam pad / removable stay 3.5 mm powder-coated LightWire frame Dyneema hardline, removable aluminum stays, padded back panel Simple frame - 1.2 oz carbon fiber / Delrin active suspension hoop
Fabric 100D & 200D Robic nylon 100D & 70D Robic nylon NanoFly: 100D nylon x 200D UHMWPE ripstop Dyneema Ultra 400, Ultra 200


Best Overall Ultralight Backpack


Gossamer Gear Mariposa 60


93
OVERALL
SCORE
  • Comfort 10.0
  • Ease of Use 10.0
  • Weight-to-Volume Ratio 8.0
  • Adjustability 8.0
Total Weight: 32.6 oz | Weight-to-Volume Ratio: 0.54 oz/L
REASONS TO BUY
Comfortable with both light and heavy loads
Versatile
Great feature set
Well made
Fits bear canister
REASONS TO AVOID
Heavier than some

Once again, against relentless competition from other brands, the Gossamer Gear Mariposa 60 holds its place at the top of the fleet. This pack balances comfort with an emphasis on lightweight design in an unparalleled way. Its feature set is thoughtful and useful but not overkill. It provides plenty of external carry options without feeling weighed down by superfluous bells and whistles. The Mariposa has our favorite stretchy center mesh pocket, which proved large enough to store extra layers, snacks, and other items we wanted to access quickly. It fits a bear canister and can carry a heavy load comfortably, yet it can also compress to carry a smaller load comfortably. The fabrics used in its design are durable and lightweight; miles of bushwhacking and talus-crossing hardly left a scratch.

Marketed as a 60-liter pack, the Mariposa can carry up to 64 liters when stuffed to the brim. For some, this may feel like too much room for an ultralight pack, as the more room you have, the more you may fill with unnecessary gear. It isn't the lightest in our review, though its 32.6-ounce total weight and 0.54 ounce per liter weight-to-volume ratio are impressive. Plus, its slightly heavier weight added a level of comfort that couldn't be beaten.

Read more: Gossamer Gear Mariposa 60 review

ultralight backpack - the ultralight gossamer gear mariposa going into the sierras.
The ultralight Gossamer Gear Mariposa going into the Sierras.
Credit: Sarah Van Cleve

Best Bang For Your Buck


Gossamer Gear Gorilla 50


85
OVERALL
SCORE
  • Comfort 10.0
  • Ease of Use 9.0
  • Weight-to-Volume Ratio 5.0
  • Adjustability 8.0
Total Weight: 31.1 oz | Weight-to-Volume Ratio: 0.62 oz/L
REASONS TO BUY
Tough but light Robic nylon construction
Can transform from a day hiker to a multi-day backpack
Great spread of features without compromising on weight
REASONS TO AVOID
Not as waterproof as other packs
Top flap may not be everyone's favorite

Once you get used to the supreme comfort of the Gossamer Gear Gorilla 50, it's hard to imagine living without it. It has great back padding, an internal aluminum frame, and an excellent hip belt. Those aren't the only reasons we love the Gorilla. Its voluminous external pockets swallow up gear so much that we rarely need to open the pack's main compartment until it's time to make camp. Even more impressive is the modular design that allows you to customize the pack for the trip's itinerary by easily stripping components off that you may not need to cut even more weight.

There's little we don't love about the Gorilla and it will be difficult for anyone to wrangle it out of our greedy thru-hiking hands. The top flap design of Gossamer Gear is unusual in our ultralight category, and you may prefer a rolltop. If you're especially rough on gear, the judicious use of mesh for the side and center pockets and holding the back padding in place may become untimely victims of your heavy-handedness.

Read more: Gossamer Gear Gorilla 50 review

Nothing reminds us of the joy of sweet simplicity than a good walk in the woods.
Credit: Justin Simoni

Best Full-Featured UL Pack


Osprey Exos Pro 55


79
OVERALL
SCORE
  • Comfort 9.0
  • Ease of Use 9.0
  • Weight-to-Volume Ratio 5.0
  • Adjustability 7.0
Total Weight: 33.2 oz | Weight-to-Volume Ratio: 0.6 oz/L
REASONS TO BUY
Super well-thought-out design and features
Great suspension system
Excellent back ventilation
REASONS TO AVOID
Heavy for an ultralight pack
Lid top may be a turnoff for rolltop lovers

We must come clean and admit we're still blown away at the amount of engineering put into the exceptional Osprey Exos Pro 55 to take a more conventional backpack design and make it sincerely ultralight. Weight may be gone, but all the creature comforts that one expects from a backpack are not left on the cutting room floor. We especially loved the back suspension system that provided comfort against our pack load and gave a ton of air circulation our poor back so desperately craves.

If you're shaving as much weight as possible from your kit, the Osprey Exos Pro 55 won't be attractive to you, but one can certainly make a proper sub-ten-pound base weight kit when using the Exos Pro, and for that, we applaud Osprey's effort. The main nylon fabric is designed to last for years, but be aware that the back mesh on the suspension system may need to be babied a little more.

Read more: Osprey Exos Pro 55 review

A comfortable pack makes for a happy, trail-eating hiker.
Credit: Justin Simoni

Best for Exceptional Durability


Hyperlite Mountain Gear Porter 55


74
OVERALL
SCORE
  • Comfort 8.0
  • Ease of Use 8.0
  • Weight-to-Volume Ratio 5.0
  • Adjustability 8.0
Total Weight: 31.5 oz | Weight-to-Volume Ratio: 0.57 oz/L
REASONS TO BUY
Lightweight yet incredibly durable
Comfortable, considering its simplistic design
Low profile, good for technical travel
Full-sized, comfortable waist belt
REASONS TO AVOID
Expensive
Few external storage options

Missions in the mountains require packs that can handle two main things. First, the pack must be able to carry heavy loads. Second, it must be burly, which means it needs to offer protection from abrasions and keep its contents safe from rain and snow. The Hyperlite Mountain Gear Porter 55 does all these with style. It's simple and sleek, with a roll-top closure and lots of external lashing options. Its side straps can accommodate skis, boots, tent poles, or ropes, while its small waist belt pockets can hold snacks, phones, and sunscreen. We liked this pack's size; it is a bit more versatile than some of its larger siblings from Hyperlite. The Dyneema fabric used in its construction makes it one of the most durable and water-resistant packs we've tested.

Unfortunately, all of this comes at a cost. Hyperlite packs are some of the priciest on the market. You'll want to be sure this is the tool you need before throwing down so much cash. Also, if you're into pockets and features and bells and whistles, this simplistic pack may be a bit disappointing.

Read more: Hyperlite Mountain Gear Porter 55 review

ultralight backpack - here, we have the porter loaded almost to max capacity.
Here, we have the Porter loaded almost to max capacity.
Credit: Alexa Flower

Best for Long Distance Thru Hikes


Ultralight Adventure Equipment Ultra Circuit


72
OVERALL
SCORE
  • Comfort 8.0
  • Ease of Use 7.0
  • Weight-to-Volume Ratio 6.0
  • Adjustability 7.0
Total Weight: 35.9 oz | Weight-to-Volume Ratio: 0.53 oz/L
REASONS TO BUY
Exquisite choice of advanced, tough, waterproof materials
Realistic load limit and great load transfer
Comfortable to wear for miles and miles
REASONS TO AVOID
Pricey
Back padding not removable

For a long-distance thru-hike, you want the perfect balance of performance and comfort. After thoroughly testing every pack in our lineup, the Ultralight Adventure Equipment Ultra Circuit aligns ideally for a long-distance thru-hike like the PCT, CDT, AT, or all three. We adored the harness/padding/hip belt system that put the pack's load mostly on our hips and off our shoulders. We loved the pack's construction, including superb abrasion-resistant and water-resistant fabrics like Ultra 200D and 400D Challenge Ultra fabric. The exterior pockets had enough for all our close-at-hand gear and elastic tops to keep things from getting dropped.

We'd love to leave it at that, but you know that no product is perfect. The back padding is curiously not removable for such a high-end pack, which cuts down on its versatility and customization. It's also quite expensive. These high-tech fabrics and impeccable construction don't come cheaply. But as part of the Big Four of thru-hiking gear, investing in a great pack is the right move.

Read more: Ultralight Adventure Equipment Ultra Circuit review

Long days in variable terrain can be a chore without a comfortable pack keeping your load feeling lighter.
Credit: Justin Simoni

Honorable Mention for Exceptional Weight to Volume


Mountain Laurel Designs Exodus 55L


56
OVERALL
SCORE
  • Comfort 4.0
  • Ease of Use 5.0
  • Weight-to-Volume Ratio 10.0
  • Adjustability 5.0
Total Weight: 16.4 oz | Weight-to-Volume Ratio: 0.30 oz/L
REASONS TO BUY
Featherlight and high volume
Waterproof Ultra fabric
Excellent design and detail
REASONS TO AVOID
Very expensive
Low load limit, especially for volume
Fiddly to make comfortable

The Mountain Laurel Designs Exodus 55L is what one may imagine — both the good and the bad — of what ultralight backpacks are all about. It has advanced composite materials whose weight rivals that of tissue paper, with slimmed-down features, minimal pockets, a cool name, and a hot price tag to match. There's a lot to unpack concerning the Exodus, but if you're an advanced hiker already possessing a streamlined kit and looking for the best weight-to-volume value on the market, the Exodus is made for you.

But if you're not yet that advanced of a backpacker and your entire carry weight is more than 20 pounds, then the Exodus won't support you as you gain the requisite experience to be the next "Flyin'" Brian, "Anish" Anderson, or Jeff "Legend". The big spoiler to the Exodus's incredible weight-to-volume ratio is that it skimps out on back padding, an internal frame, as well as other niceties like hip belt pockets, making you figure those details out yourself using clever packing and repurposing gear. If that's too much of a puzzle to solve on top of all the other logistics of a big-thru hike, consider another ultralight backpack that better supports your adventure, both literally and figuratively.

ultralight backpack - the mountain laurel designs exodus 55l (seen here with additional...
The Mountain Laurel Designs Exodus 55L (seen here with additional accessories) is a finely-tuned long trail crusher, but make sure it's the right amount of pack for your experience and goals.
Credit: Justin Simoni


Compare Products

select up to 5 products to compare
Score Product Price
93
Gossamer Gear Mariposa 60
Best Overall Ultralight Backpack
$285
Editors' Choice Award
85
Gossamer Gear Gorilla 50
Best Bang For Your Buck
$255
Best Buy Award
79
Osprey Exos Pro 55
Best Full-Featured UL Pack
$290
Top Pick Award
74
Hyperlite Mountain Gear Porter 55
Best for Exceptional Durability
$389
Top Pick Award
74
Ultralight Adventure Equipment Ohm 2.0
$260
72
Ultralight Adventure Equipment Ultra Circuit
Best for Long Distance Thru Hikes
$380
Top Pick Award
72
Durston Kakwa 55
$260
70
Granite Gear Crown3 60
$240
68
Ultralight Adventure Equipment Circuit 68
$280
67
Chicken Tramper 35 Ultralight
$275
66
Hyperlite Mountain Gear Southwest 55
$379
63
Gossamer Gear Murmur 36 Hyperlight
$185
62
Ultralight Adventure Equipment CDT
$200
56
Mountainsmith Zerk 40
$220
56
Mountain Laurel Designs Exodus 55L
Honorable Mention for Exceptional Weight to Volume
$325
52
Granite Gear Virga3 55
$200

ultralight backpack - the mariposa out for a few days hiking through the backcountry of...
The Mariposa out for a few days hiking through the backcountry of Grand Teton National Park. The pack has ample room in the side pockets for stoves, bottles, and food, while the mesh pocket is large enough for a few extra layers.
Credit: Jane Jackson

Why You Should Trust Us


Over the past nine years, our testing process still begins with deep research into the market to see what's out there. After we make our selection, we purchase all the products at retail prices to eliminate bias from our reviews. Our ultralight backpack testing protocol consists of both lab testing and trail miles. We independently verify weight and volume measurements. We take it a step further by scoring packs based on their weight per unit volume, allowing us to compare different volumes fairly. On-trail testing included trips such as 260 winter miles on the AT and 40 miles in the Black Rock Canyons Wilderness in Colorado. We spent time in Patagonia, the Continental Divide Trail, and the Sierra High Country. Additionally, we made direct comparisons using 15 and 30-pound weights for shorter test laps.

Our ultralight backpack testing is divided into four different metrics:
  • Comfort (40% of overall score weighting)
  • Ease of Use (25% weighting)
  • Weight-to-Volume Ratio (20% weighting)
  • Adjustability (15% weighting)

This review is the combined efforts of several GearLab ultralight experts. Jane Jackson and Brandon Lampley bring to the table a wealth of related experience. For 200+ days a year, you can find Jane outside using and testing gear. With years spent working and playing in the Yosemite backcountry, the Tetons, and the Wind River Range, as well as trips taken to the Alaska Range, the Himalayas, and Patagonia, she has spent plenty of time under the burden of a heavy pack. Brandon has hiked both the Pacific Crest Trail and Appalachian Trail, essentially back-to-back, with only four months off in between. He also has first ascents to his name in the Indian Himalayas and has summited Denali and Ama Dablam. Justin Simoni lends his deep knowledge and vast experience to this review, gained from his time in the Colorado backcountry. Justin has done fast-and-light missions on the very ridge of the Continental Divide, the Sangre de Cristo Range, and the Mosquito-Tenmile Range. With no external support, he has summitted all the Colorado 14ers and Centennials in two separate years. He can be heard quietly muttering about an unsupported FKT (fastest known time) of the Colorado Trail after his daily high-elevation-gain trail runs.

The ULA Ultra Circuit feels like a best friend on the trail, always...
The ULA Ultra Circuit feels like a best friend on the trail, always supporting your long-distance outdoor adventures.
Cinch straps on the main pack body a pack help add versatility for...
Cinch straps on the main pack body a pack help add versatility for long thru hikes as well as shorter day trips in the mountains.
We took all these packs on a variety of outdoor adventures to help you find the best pack for you.

Analysis and Test Results


In the past six years, we've tested over 40 ultralight models in addition to hundreds of the best backpacks of all styles. The products we've included this year represent the cutting edge in ultralight technology. If you're looking for larger frames and luxury padded waistbelts, look elsewhere; the packs in this review hardly resemble a traditional backpacking pack. Many exciting small brands have popped up in this category of outdoor gear over the past few years, and we've had fun assessing their latest products. Here, we evaluate the top products available for multi-month thru-hiking adventures and shorter alpine trips focused on fast and light backcountry travel.


Value


When making an outdoor gear purchase, we often trade off one thing for another, and no one understands trade-offs better than an ultralight enthusiast. We all spend too much time "weighing" our options. To bring a slightly thicker sleeping pad can mean foregoing powdered milk in the coffee — decisions, decisions. However, ultralight packs continue to get better and more comfortable as time passes. The Gossamer Gear Gorilla offers impressive comfort and versatility for a reasonable price. The Gossamer Gear Mariposa isn't much more expensive but is our favorite all-around ultralight backpack. Alternatively, the ULA Ultra Circuit is more expensive but is also made of durable materials designed to last for a long time through trying conditions.

ultralight backpack - the gossamer gear gorilla packed with equipment, food, and fuel for...
The Gossamer Gear Gorilla packed with equipment, food, and fuel for a five-day wintertime section of the Appalachian Trail. We covered a lot of miles to find the best ultralight backpacks. From the packing tests seen here, to the independent weight and volume measurements in our lab, we've done the most thorough side-by-side testing.
Credit: Brandon Lampley

Comfort


Of course, we all want an ultralight pack to be featherlight, but it must carry our load comfortably to be worth it. For each of these packs, we judged load-carrying comfort for two loads: 15 and 30 pounds. We then averaged each pack's performance in both categories to generate our carrying comfort score. Fifteen pounds is a perfect comparison weight for ultralight hikers on a short trip. Thirty pounds is a fair comparison weight for lightweight hikers on shorter trips, ultralight hikers carrying a week's worth of food, or those brave enough to travel in the winter. While some packs can be stripped of their frame and waist belt, our evaluation of "great, good, or poor" for carrying 15 and 30 pounds is with the frame and waist belt in use, as these features add significantly to the comfort of carrying comfort a pack. We only recommend stripping down a pack completely when carrying 12 pounds (or less) in total weight.


The Gossamer Gear Mariposa and Gossamer Gear Gorilla earned our highest scores in this category. With hip belts and back pads on, these packs are impressively comfortable, well-balanced, and secure to carry. They are some of the easiest and most comfortable packs to strip off their frame and waist belts for loads under twelve pounds. The Osprey Exos Pro 55 is nearly as comfortable but for different reasons. Its tensioned mesh back panel and wrap-around non-removable belt help to carry the load far better than most other solutions in the ultralight world.

ultralight backpack - nearly every day out with these packs, we put them on the scale...
Nearly every day out with these packs, we put them on the scale before hiking, noting how well each carries 15 or 30 pounds (and the loads in between). At the end of our testing period, we also loaded each pack with 30 pounds, and hiked the same hill up and down to confirm our field testing.
Credit: Brandon Lampley

The ULA Ultra Circuit and Hyperlite 3400 Porter also scored well when it comes to comfort. Both have cushy back padding built in to keep your gear from poking you with every step.

To simplify our findings for load-carrying comfort even further, we've broken down some of our award winners' niches as far as load-carrying comfort goes:
  • Best for 10-20 lb loads: Mountain Laurel Designs Exodus 55
  • Best for 15-25 lb loads: Gossamer Gear Gorilla and Mariposa
  • Best for 35+ lb loads: Hyperlite Mountain Gear Porter

The ULA Circuit, ULA Ohm 2.0, and Chicken Tramper 35 Ultralight also offer above-average comfort. Both ULA models have good back padding, while the Chicken Tramper custom builds their packs to your exact body measurements, ensuring a perfect fit every time.

ultralight backpack - the ohm 2.0 has good back padding, making it a fairly comfortable...
The Ohm 2.0 has good back padding, making it a fairly comfortable pack for even long journeys.
Credit: Brandon Lampley

The Durston Kakwa 55, Granite Gear Crown3 60, and Hyperlite Mountain Gear Southwest 55 are more decently comfortable packs. They each straddle the line between comfortable hip belts and shoulder pads without offering too much padding that they're extra heavy. Of course, that makes them less comfortable than the more thickly padded packs earning top scores in this metric, but these three are still solid contenders.

ultralight backpack - the durston kakwa maintains decent comfort while still being...
The Durston Kakwa maintains decent comfort while still being lightweight.
Credit: Justin Simoni

Ease of Use


How easy is it to use the features of the pack? Similar to comfort, what's the point of a specialized pack if you need an advanced degree in spatial awareness to use it? We used every pocket repeatedly to see how conveniently they were located, how easily they were accessed with and without removing the pack, and how versatile they are for different types of trips and different styles of packing.


The one-two punch of the Gossamer Gear Gorilla and Gossamer Gear Mariposa again get top honors in this metric. We found both models intuitive to use as soon as you throw them on your back, yet both have the features we like to see in more advanced packs. Standout details include the very voluminous center pocket that swallows up even large gear.

ultralight backpack - the center and side pockets are just some of the features that...
The center and side pockets are just some of the features that really set the Gorilla apart from the rest.
Credit: Justin Simoni

Not to be outdone, the Osprey Exos Pro 55 also delivers when it comes to being a no-brainer to use. The Exos Pro is very "Batteries Included," and for a small weight penalty, it just works without too much fiddling about. If you're transitioning to ultralight from a more conventional backpack, this pack makes the transition utterly painless.

ultralight backpack - the exos pro side pockets are easy to work with, either while the...
The Exos Pro side pockets are easy to work with, either while the pack is on the ground or even while on your back -- no advanced yoga practice required.
Credit: Justin Simoni

On the opposite side of the ultralight spectrum is the Hyperlite 3400 Porter, which in its own right is also easy to use but can grow with you like Lego blocks. Need more carrying capacity of any sort? Just lash on whatever you need. It has the utmost flexibility in carrying your gear while being super burly to boot. The Durston Kakwa 55 also has some well-thought-out features that are a joy to use.

The Durston Kakwa 55 comes ready to go for your next long distance hike.
Credit: Justin Simoni

The ULA Ohm 2.0 can fit an impressive eight Clif Bars into each of its hip pockets. The Granite Gear Crown3 60 has a lid with a brain, for those folks who love that feature. It can also fit five Smartwater bottles in each of its side pockets. The ULA Ultra Circuit is also impressive, though holds just 4 700-milliliter Smartwater bottles in each of its side pockets. The Gossamer Gear Gorilla and Mariposa, Osprey Exos Pro, Hyperlite Porter and Southwest, Chicken Tramper 35, Mountainsmith Zerk 40, and Mountain Laurel Exodus all have whistles attached to their sternum straps.

ultralight backpack - the mountainsmith zerk has a whistle on the sternum strap and...
The Mountainsmith Zerk has a whistle on the sternum strap and shoulder pockets that can easily fit these 700-milliliter Smartwater bottles.
Credit: Justin Simoni

Weight-to-Volume Ratio


The weight-to-volume ratio is a measurement used to compare packs of differing volumes. This metric gets straight to the point; how much does this pack weigh relative to the volume it carries? We measured the weight of each model on our digital scale, as well as each of its disparate parts.


Then, we measured pack volume, as well as the volume of the main exterior pockets. This gives us a normalized way to compare packs from different manufacturers using the same rules. We were sometimes very surprised at how different the advertised total volume was from what we measured.

We measured the internal volume of the Durston Kakwa 55 using ping...
We measured the internal volume of the Durston Kakwa 55 using ping pong balls to be around 40L.
The external center pocket of the Durston Kakwa 55 is a stretchy...
The external center pocket of the Durston Kakwa 55 is a stretchy mesh that expands when you add gear. The mesh is useful for drying out wet clothes.
Ping pong balls ruled the roost when measuring the internal volume of various pockets of these packs.

Finally, we calculated the weight-to-volume ratio to compare each pack directly, regardless of volume, to get a fair idea of how light these packs really are. All the packs in the ultralight category faired extremely well when looking at their weight-to-volume ratios, but there certainly are some standouts.

ultralight backpack - the large pack volume of the mountain laurel exodus is attained with...
The large pack volume of the Mountain Laurel Exodus is attained with an extra-long roll top. Given the manufacturer's low 20-pound load limit, you may find it difficult to fully pack this main compartment.
Credit: Justin Simoni

Top honors go to the Mountain Laurel Exodus 55, with its seriously low weight-to-volume ratio of just 0.3 ounces per liter. It's built as a fast-and-light pack that practically dares you to break long trail hiking records. The Exodus has minimal features, smaller exterior pockets, and a large main pack compartment. It uses lightweight but tough 3.5 ounces per square yard Ultra 200D fabric.

ultralight backpack - the murmur is designed for those who take ultralight backpacking...
The Murmur is designed for those who take ultralight backpacking seriously and whose base weight is down to 10 pounds or so.
Credit: Eric Bissell

Not trailing far behind is the Gossamer Gear Murmur 36 Hyperlight boasting 0.35 ounces per liter. This bag is a smaller 36-liter pack that's made of thin 30D Cordura & 70D Robic nylon. The Durston Kakwa 55, another pack made with Ultra 200D fabric material, also comes in at a respectable 0.42 ounces per liter.

The Durston Kakwa 55 uses Ultra 200 fabric to make a very lightweight pack, especially for the amount of internal space it can accommodate your gear with.
Credit: Justin Simoni

The ULA Ohm 2.0 also vies for attention with its great weight-to-volume ratio of 0.5 ounces per liter. We measured both the ULA Ultra Circuit and Granite Gear Crown3 60 at 0.53 ounces per liter. The Gossamer Gear Mariposa came in at 0.54 ounces per liter, quickly followed by the Granite Gear Virga3 55 at 0.55 ounces per liter.

ultralight backpack - the granite crown3 has a ton of internal storage in a lightweight...
The Granite Crown3 has a ton of internal storage in a lightweight package.
Credit: Justin Simoni

Adjustability


Adjustability tests how well a pack conforms to your body, how well it adapts to different adventures, and how well it carries the usual suspects of backpacking gear. We asked ourselves: is this pack working with or against us in the adventures we want to bring it along? We also considered sizing and customization options available during the ordering process.


One of the most adjustable packs to work with the largest spectrum of body types is the Granite Gear Crown3 60. It features a hyper-adjustable hip belt that can be used in conjunction with its top lid to transform into a hip pack for day trips from base camp. The Granite Gear Virga3 also has this exceptionally adjustable hip belt, though it lacks the removable brain to transition to a day pack.

ultralight backpack - some shoulder straps can accommodate an incredible range of both...
Some shoulder straps can accommodate an incredible range of both torso height and width.
Credit: Justin Simoni

The Gossamer Gear Mariposa and Gossamer Gear Gorilla both scored highly for adjustability, with an incredible amount of modularity in both of their similar designs, which allows them to be worn comfortably — depending on load — with or without their back padding, internal frame, or hip belt. Both of these packs can also be purchased with "mix and match" hip belts, allowing you to order your perfect combination of sizes. This customization is also available for all the ULA packs we tested (the Ohm 2.0, Ultra Circuit, Circuit, and the CDT) as well as the Chicken Tramper 35.

The Gorilla is modular, allowing you to separate and use the main...
The Gorilla is modular, allowing you to separate and use the main pack body apart from the hip belt, back padding, and metal frame.
The Mariposa is modular, allowing you to separate and use the main...
The Mariposa is modular, allowing you to separate and use the main pack body apart from the hip belt, back padding, and metal frame.
Both the Gorilla and Mariposa have removable back padding, internal frame, and hip belt.

The Hyperlite Porter adjusts to suit your needs in a very different way, featuring a plethora of daisy-chained webbing on its exterior for you to lash on almost anything you can think of. Its load limit is rated quite high, so feel free to pile on the gear and accessories.

ultralight backpack - where will your perfect ultralight backpack take you?
Where will your perfect ultralight backpack take you?
Credit: Justin Simoni

Conclusion


We hope the information in this review sparks an interest in the ultralight world. If all the gear required feels overwhelming, simply getting a lightweight pack is a wonderful place to start. A light pack automatically jumpstarts the transition toward lightening up the rest of your kit. The packs in this review range from extremely slimmed down to more comfy options for those unwilling to part with the standard backcountry creature comforts. Our testers have worn loads of different packs within and outside the ultralight world, bringing a breadth of experience to help guide you toward the pack that is right for you.

There are all kinds of ways to shed some weight from your backpack's load — for example, you may trade in your clunkier hiking boots for top trail running shoes or a low-profile pair of the best hiking shoes. If you're seeking an best ultralight tent or a lightweight sleeping bag, we have recommendations for the best backpacking gear to start you in the right direction.

Jane Jackson, Brandon Lampley & Justin Simoni