Best Backpack For Thru Hiking

What base weight means and why the frame follows it

Base weight is the weight of all your gear minus consumables such as food, water and fuel.¹ The Appalachian Trail Conservancy also notes that the pack, shelter and sleeping bag, the 'big three', are usually the heaviest items, which is why the page suggests buying your shelter and sleep system before the pack.¹ Gossamer Gear, a pack maker, labels a base weight under 20 pounds lightweight, under 10 pounds ultralight and under 5 pounds superultralight.² Zpacks says ultralight is generally agreed to mean 10 pounds or less.³ These are industry conventions from gear makers, not a formal standard, but they line up with the page's point that frameless packs suit base weights under roughly 10 pounds.

Consumables are what push a frameless pack past its comfort zone. One liter of water has a mass of about 1 kilogram, roughly 2.2 pounds,⁴ so a four-liter desert carry adds nearly 9 pounds. A bear canister adds weight and bulk too: Denali's small loaner canister weighs 3 pounds and holds 3 to 5 days of food for one person.⁵ Where canisters are required depends on the park and the area. Sequoia and Kings Canyon, for example, require them from May 1 to October 31 in specific areas and recommend them across both parks,⁶ so check current rules for each section. REI notes frameless packs save weight but are much less comfortable under heavy loads,⁷ which is why the heaviest stretch of the trail, not the average, should decide the frame.

How heavy thru-hiking packs really get

The idea that a pack should weigh no more than 20% of your body weight is a hiking-community rule of thumb with no primary research behind it. When researchers weighed Appalachian Trail long-distance hikers' packs, men carried an average of 19.6 kg and women 17.3 kg, which worked out to 25.0% and 27.9% of body weight.⁸ Other sources give very different limits. Deuter, a pack maker, says people can carry a maximum of 20 to 25% of their body weight,⁹ while a 2022 review of backpack ergonomics says adult loads should generally not exceed 40% of body mass.¹⁰

Lower numbers still matter on a trail you walk every day for months. In a 2026 study of long-distance hikers, packs heavier than about 10% of body weight produced a clear, load-dependent rise in pressure under the feet.¹¹ A lab study found energy use while walking rose roughly in step with pack weight, by about 7.6 watts for each extra kilogram.¹² Neither finding sets a hard limit, but together they explain why thru-hikers trim base weight even when a heavier load feels fine on day one.

Dyneema versus nylon: what the evidence shows and what it doesn't

Dyneema is a brand of ultra-high-molecular-weight polyethylene fiber.¹³ In its composite fabrics, layers of that fiber are bonded at 0 and 90 degrees, and the maker says the result won't absorb water or stretch over time.¹⁴ Nylon, by contrast, is defined under US labeling rules as a fiber made from a long-chain synthetic polyamide.¹⁵ The denier numbers on nylon packs describe yarn weight: denier is the weight in grams of 9,000 meters of yarn, so 210D yarn is heavier than 100D.¹⁶

Some guides claim that Dyneema composite wears less predictably on granite, while Robic nylon resists abrasion better; that reflects common hiker opinion rather than a published comparison; no independent long-term comparison in the sources reviewed for this guide backs it. Makers argue both ways. Hyperlite says its woven Dyneema composite is more abrasion- and tear-resistant than its earlier fabrics,¹⁷ and Dyneema says its fiber makes packs more resistant to cuts and abrasion.¹³ Warranty terms are a practical tie-breaker. Gossamer Gear, for example, does not warranty fabric failure due to durability,¹⁸ so read the fine print on any pack you plan to wear out over 2,000 miles.

Fit can also change as the miles add up. Osprey says a correctly sized hipbelt leaves a 3 to 6 inch gap between the hip-pad tips when tightened.¹⁹ If you lose weight on trail and that gap closes to nothing, the belt can no longer grip your hips, and a swappable belt size becomes worth more than a few saved ounces.