Thru-Hike Pack Guides: Complete Guide
Comprehensive technical analysis of sizing, materials, installation requirements, and manufacturer standards for thru-hike pack guides.
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In plain English
A thru-hike means walking an entire long trail, such as the Appalachian Trail, in one go. It often takes several months. Along the way, hikers walk into towns every few days to buy more food, which is called resupplying.
That shapes the backpack. You do not need room for six months of food, only for the food between one town and the next. So the right pack size depends on the longest gap between towns on your trail. On some trails that gap is three days; on others it can be more than a week.
Long trails also wear gear out. Zippers, buckles and mesh pockets get used thousands of times, so hikers favor simple packs with few moving parts. Lighter gear helps too, because every pound is carried for months.

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A thru-hike pack should be sized to a hiker's longest stretch of food carried between resupply points, not to the trail's total mileage or a generic capacity chart. The Appalachian Trail, Pacific Crest Trail, Continental Divide Trail, and John Muir Trail each set different demands: trail length, terrain, resupply spacing, and rules like a mandatory bear canister all push pack size and build in different directions. A hiker who matches capacity to the longest carry on their specific trail avoids hauling unused space for months while still having enough room on the one stretch that actually needs it. This guide compares pack choice on the AT, on the PCT and CDT, explains how resupply length translates into liters, and covers what holds up over thousands of trail miles.
Most Appalachian Trail thru-hikers carry a 55- to 65-liter pack for the first several hundred miles, since a spring start means bulkier warm layers and Georgia's early resupply towns still sit fairly close together, then many hikers downsize to a 45- to 55-liter pack once they mail home extra gear at a shakedown stop.
Mountain Crossings at Neel Gap, roughly 30 miles into the trail, is where a large share of northbound AT hikers do a first real gear shakedown, cutting pack weight and often swapping to a smaller pack once their kit is dialed in. AT resupply towns sit close together for most of the trail, and food carries of three to five days cover the majority of the route. The one major exception is Maine's 100-Mile Wilderness, the AT's longest stretch without a town or road-accessible resupply, where hikers often carry four to eight days of food depending on pace and whether they arrange a food drop. The AT's humid, wet climate and rooty, rocky, constantly up-and-down tread favor fast-drying fabric and a pack that rides stably on steep grades over raw water capacity. Packs like the Osprey Exos and Eja, the ULA Circuit, and more structured options such as the Gregory Baltoro or Deva all see regular AT use, with hikers who want extra hipbelt padding on the AT's rocky terrain often leaning toward the heavier end of that range.
Pacific Crest Trail hikers typically run smaller, lighter packs in the 40- to 55-liter range, matching the trail's graded tread and a hiking culture built around low base weights, while Continental Divide Trail hikers commonly size up to 55 to 65 liters for the CDT's longer, more remote resupply stretches and navigation gear.
The PCT's well-graded, switchbacked tread and a hiking community that emphasizes low base weight both push average pack size down compared with the AT. Two PCT-specific factors add bulk despite that: bear-canister rules through much of the Sierra Nevada corridor (they vary by area: Sequoia and Kings Canyon require containers in specific areas, and Inyo National Forest has year-round food-storage rules), and the extra water capacity Southern California's desert sections demand, which often fills side pockets with additional bottles for miles at a stretch. The CDT is the least developed and least signed of the three long trails discussed here, following a braided route of official trail and cross-country alternates that calls for more navigation tools and, often, a slightly heavier overall kit than the PCT. It also produces the longest average food carries of the three trails: Wyoming's Great Divide Basin, New Mexico's Gila River corridor, and Montana's Bob Marshall Wilderness are all stretches where hikers regularly carry a week or more of food between towns. ULA Equipment's CDT pack was built directly around that trail's longer carries and higher average loads, and it appears alongside the ULA Circuit and Granite Gear Crown3 among CDT hikers who want more frame structure than the lightest frameless packs offer.
Pack capacity should track the longest food carry a hiker expects, not the trail's total distance: capacity is commonly planned by adding space for each additional day of food beyond a base three- to four-day resupply cycle, layered on top of the volume needed for a three-season sleep system, shelter, and clothing.
For most three-season thru-hikers, a sleep system, shelter, clothing, and cook kit take up a substantial share of the pack before food goes in, which is why food-carry length, more than gear list, drives most of the capacity difference between trails. The table below compares typical pack capacity and the longest common food carry across the four trails covered in this guide.
| Trail | Typical Length | Common Pack Capacity | Longest Typical Food Carry |
|---|---|---|---|
| Appalachian Trail | ~2,190 miles | 45-65L | 4-8 days (100-Mile Wilderness, Maine) |
| Pacific Crest Trail | ~2,650 miles | 40-55L | 5-8 days (High Sierra stretch) |
| Continental Divide Trail | ~3,100 miles | 55-65L+ | 6-9+ days (Great Divide Basin, Wyoming) |
| John Muir Trail | ~210 miles | 50-65L | 5-7 days between resupply points |
Total pack weight, including food and water, is generally kept close to 20% of a hiker's bodyweight for a sustainable carry, and a well-fitted hipbelt — sized correctly using a torso measurement from the C7 vertebra to the iliac crest — carries, by a common rule of thumb, roughly 80% of that load, not the shoulders.
Thru-hike packs need fabric and hardware that survive months of daily abrasion: most mid-weight options use 100- to 210-denier high-tenacity nylon body fabric with heavier reinforcement at the base and side pockets, while ultralight Dyneema Composite Fabric (DCF) packs trade some abrasion resistance for lower weight and built-in waterproofness.
Many thru-hike packs use a single aluminum stay or a perimeter wire frame instead of a full dual-stay frame, since most thru-hikers keep base weight under roughly 15 to 20 pounds. A trampoline-style mesh back panel, common on packs like the Osprey Exos and Eja, adds ventilation that matters most on humid trails like the AT. Zippers, hipbelt buckles, and mesh side pockets tend to fail before the main body fabric does, since they see the most repeated flexing and abrasion over a multi-month hike. DCF packs from Hyperlite Mountain Gear and Zpacks hold up well against rain, while nylon packs from Gossamer Gear and Granite Gear use a more familiar woven fabric at a small weight cost, so fabric choice often comes down to a trail's specific terrain as much as overall weight goals.
Go Deeper
Detailed companion guides for thru-hike pack guides.

Best Backpacks For The Appalachian Trail
Buyer's guide: best backpack for appalachian trail.
Best Backpacks For The Pacific Crest Trail
Buyer's guide: best backpack for pacific crest trail.
Best Backpacks for the CDT
How to choose a backpack for the Continental Divide Trail, covering capacity, frame type, fabric durability, and the CDT's long, remote resupply stretches.
Best Backpacks for the John Muir Trail
How to choose a backpack for the John Muir Trail, covering bear canister space, Sierra Nevada resupply points, and capacity for a 2-3 week hike.
International Trek Packs
Related trails & trip guides guide.
Trip-Length Capacity Guides
Related trails & trip guides guide.
The 20% and 80% figures, checked against the evidence
This page says total pack weight is generally kept near 20% of body weight and that a hip belt carries roughly 80% of the load. Both are common in hiking guidance, but neither is a settled finding. The 20% figure has no primary research source; it is a hiking-community rule of thumb. When researchers measured Appalachian Trail long-distance backpackers, packs averaged 25.0% of body weight for men and 27.9% for women, above the popular guideline.1 Deuter, a manufacturer, says people can carry a maximum of 20 to 25% of their body weight, while a 2022 review of adult load carriage says loads should generally not exceed 40% of body mass.2,3
The hip share is contested too. The Washington Trails Association says a hip belt moves around 80% of pack weight to the hips, while US Army doctrine says that with a frame and hip belt about 30% rides on the hips and lower back and 70% on the shoulders.4,5 What the research agrees on is direction: the hip region tolerates pack pressure much better than the shoulders.6
Load ratings on lightweight packs
Capacity in liters is only half the sizing question on a long food carry; the other half is the weight the frame is built for. Several packs popular with thru-hikers publish modest limits. Gossamer Gear rates the Mariposa 60 at a 30-pound recommended comfort load and 35-pound maximum, and ULA gives the Circuit a 35-pound maximum load.7,8 ULA says the Circuit has been the most popular Pacific Crest Trail pack for four years, citing the Halfway Anywhere survey.8 Granite Gear rates the Crown3 60 at 35 pounds with its framesheet and 43 pounds with the optional aluminum stay.9
Those numbers matter most on the longest carries this page lists, such as the 100-Mile Wilderness or a High Sierra stretch with a canister, where food and water can push a light pack past its rating. The low base weights that make these packs work are well documented: ULA's founder says his PCT thru-hike took him from a 25-pound to a 12-pound base weight.10 Gossamer Gear defines lightweight backpacking as a base weight under 20 pounds and ultralight as under 10.11
Bear canister rules in the Sierra
This page notes that bear-canister rules apply through much of the Sierra corridor and vary by area. The details are narrower in some places and broader in others. In Sequoia and Kings Canyon, the Park Service requires containers from May 1 to October 31 in specific areas, including Dusy Basin and the Rae Lakes Loop, and highly recommends them throughout both parks.12 In the Inyo National Forest, food storage rules apply year-round in all wilderness areas; where canisters are not mandatory, food may be counterbalance-hung at least 15 feet up and 10 feet from the trunk, otherwise a container is required.13 Yosemite bans hanging food everywhere in the park.14
Rules change, so check each agency's current page before a trip. For pack sizing, a canister's volume is fixed: Glacier Bay's loaner holds 560 cubic inches, about six days of food for one person, and weighs 2.8 pounds.15

