By Priya Anand, Backpacking Gear Research Writer · Published September 14, 2026, 6:03 PM ET
Direct Answer
A five-day trek without resupply typically needs a 60L to 75L backpack, since roughly 7.5 to 12.5 lbs of food alone takes up significant volume alongside a standard camping kit. A planned resupply, or an ultralight gear list, can bring that down to 55–65L.
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In plain English
A five-day trek means four nights out and five days of walking. If there is no town or shop along the way, you carry all five days of food from the very start. That is the big difference from a weekend trip.
Your tent, sleeping bag and stove are the same size whether you go for two nights or four. Food is what grows. Picture five days of breakfasts, lunches, snacks and dinners piled on a kitchen table. That pile needs its own space in the pack, and it is heaviest on day one.
Because of that, packs for five-day trips are usually larger, around 60 to 75 liters, with a sturdier frame inside to carry the extra weight. If you can pick up more food halfway, called a resupply, you carry less at once and can use a smaller pack.
A five-day trek without resupply typically needs a 60L to 75L backpack, since roughly 7.5 to 12.5 lbs of food alone (at 1.5 to 2.5 lbs per person per day) takes up significant volume alongside a standard shelter, sleep system, and cook kit. Food volume, not gear bulk, is usually the deciding factor at this trip length.
Why five days is a step up from a weekend trip
At two or three nights, food and gear both fit comfortably in a 45–55L pack. By five days, cumulative food weight and volume push noticeably higher, and packing efficiency starts to matter more: repackaging food out of bulky retail wrapping and choosing calorie-dense, low-volume meals can meaningfully reduce how much space five days of food actually needs.
Does a resupply change the answer?
Yes. A five-day trek with a planned resupply partway through only needs to carry food for the days between stops, which can bring required capacity back down to the 55–65L range typical of a shorter unsupported trip. This is a key reason two five-day treks can call for very different pack sizes depending on route planning.
Ultralight vs traditional packing for five days
Packing Style
Typical Capacity for 5 Days, No Resupply
Traditional 3-season kit
65–75L
Efficient 3-season packing
60–65L
Ultralight, low base weight
50–60L
Other factors that push capacity higher
A five-day trek requiring a bear canister, common in many wilderness areas with high food-storage regulations, adds rigid, non-compressible volume that pushes many hikers toward the upper end of this range regardless of how efficiently the rest of the kit packs down. Cold or shoulder-season conditions add a similar effect through bulkier insulation.
Bottom line
Plan for 60–75L for an unsupported five-day trek with a standard kit, adjust down toward 55–65L with a resupply or a lighter gear list, and confirm torso length and hipbelt fit before finalizing size, since a pack's comfort at that loaded weight depends on fit as much as liter count.
Where the food numbers come from
The food estimate on this page, 1.5 to 2.5 pounds per person per day, is a hiking-community rule of thumb rather than a published standard, and none of this site's verified sources gives an official per-day backpacking food weight. The most detailed calorie figures come from the military. A National Academies report puts energy needs in cold environments at 3,400 to 4,300 kcal a day for soldiers, and notes that snow, bulky clothing, boots and packs raise the energy cost of activity.5 Those are cold-weather field numbers, not a hiking target.
For ordinary three-season trips, the Compendium of Physical Activities rates backpacking at 7.0 METs, which works out to about 7 kcal per kilogram of body weight per hour on the trail.6,7 Research on long endurance events suggests the gut can only supply about 2.5 times basal metabolic rate over sustained periods, with the rest drawn from body stores.8 Carrying more food than you can realistically eat only adds weight.
Canister capacity and five days of food
Food-storage containers turn the five-day question into a hard volume limit. Denali's small container weighs 3 pounds and holds 3 to 5 days of food for one person, while its larger model weighs 5 pounds and carries 7 to 10 days.2 New York's DEC describes typical canisters as about 8 by 12 inches, holding up to five days of food.9 Glacier Bay's 560-cubic-inch loaner holds about six days.10 A five-day trek with a small canister leaves no slack, so compact, calorie-dense food matters more than it does on a weekend.
Rules differ by place and change over time. Denali requires containers for overnight camping in most of its backcountry units,2 and Inyo National Forest applies food-storage rules year-round in all its wilderness areas.11 Check the managing agency's current page before planning.
Weight, frames and load ratings
Day-one weight on a five-day trek is the heaviest you will carry, and it often exceeds tidy guidelines. Appalachian Trail long-distance backpackers in one study carried packs averaging 25% of body weight for men and about 28% for women.12 Deuter says people can carry a maximum of 20 to 25% of body weight,13 which makes the popular 20% figure a conservative rule of thumb rather than a hard limit.
That is also why frame ratings matter more than liters at this trip length. REI says frameless packs are much less comfortable under heavy loads,4 and it rates its tubular-aluminum-framed Traverse 60 for loads up to 45 pounds.3 Granite Gear's Crown3 60 shows how much the frame changes things: rated 25 pounds without its framesheet, 35 with it and 43 with the optional aluminum stay.14 Match the rating to your heaviest day, not your average one.
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