By Priya Anand, Backpacking Gear Research Writer · Published September 14, 2026, 6:03 PM ET
Direct Answer
A week-long hike (six to seven nights) typically needs 65 to 75 liters, built from base gear plus roughly 10 to 17.5 liters of food and fuel using the common estimate of 1.5 to 2.5 liters of pack space per day of food. Resupplying mid-trip can lower that need toward 55 to 65 liters.
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In plain English
A week-long hike means about six or seven nights camping, often far from any shop. The size of pack you need comes down to one simple question: how many days of food do you have to carry at once?
If you carry all seven days from the start, the pack has to hold a lot of food on the first morning, and it gets lighter every day as you eat. If you can pick up a box of food halfway, maybe from a small store or a ranger station, you only ever carry three or four days, and a smaller pack works.
Some places also make you store food in a hard plastic container that bears can't open. It's roughly the size of a large coffee canister, and it takes up the same space whether it's full or empty.
A week-long hike typically needs 65 to 75 liters of pack capacity. That figure comes from a standard base gear list — shelter, sleeping bag, pad, stove and cook kit — combined with roughly 10 to 17.5 liters of food and fuel volume across six to seven nights, using the common planning estimate of 1.5 to 2.5 liters of pack space per day of food.
Resupply plans change this number meaningfully. A hiker restocking food at the trip's midpoint only carries three to four days of food at any given time rather than a full week, which can lower the practical capacity need to 55 to 65 liters even though the total trip still spans a week. A fully self-supported week with no resupply point sits at the higher end of the range or beyond it.
What pushes a week-long hike above 75 liters?
A required bear canister, which adds a fixed volume block that doesn't compress
Winter or shoulder-season insulation — a warmer sleeping bag and extra layers
A bulkier, non-compressible tent or sleeping pad
Carrying gear for a companion, child or dog on the same pack
Hikers with a lighter base weight and more compressible individual items — common among experienced backpackers running an ultralight setup — can often complete the same week-long trip in 50 to 60 liters. New backpackers planning their first week-long trip are better served sizing toward 70 to 75 liters, since spare room is easier to manage than gear strapped to the outside of an undersized pack.
Checking the food-volume estimate
The page's 1.5 to 2.5 liters of pack space per day of food is a common planning estimate, not a measured standard. Park canister ratings give a useful cross-check. Glacier Bay's loaner canister holds 560 cubic inches, about 9 liters, and is rated for about six days of food for one person,1 which is roughly 1.5 liters a day. Denali's small canister holds 3 to 5 days of food and its larger one 7 to 10 days.2 Those ratings assume compact, carefully packed food, so the page's upper figure is a fair allowance for bulkier meals and packaging.
Resupply cuts the peak load, not just the average. A midpoint resupply roughly halves the maximum food you carry at once, which is where the page's 55 to 65 liter figure comes from. Stores and mail pickups keep irregular hours, so size the pack for the longest stretch you might actually end up carrying, not the ideal plan.
Canisters set a fixed floor
Where a canister is required, its dimensions decide more than the food list does. Denali requires all food, garbage and scented items to be stored in a bear-resistant container when camping overnight in most backcountry units; its small container weighs 3 pounds and its larger one 5 pounds.2 Rules vary widely elsewhere. In Sequoia and Kings Canyon, containers are required May 1 to October 31 only in named areas and highly recommended throughout both parks,3 while hanging food is illegal everywhere in Yosemite.4
A full week of food can overflow a small canister, so some hikers carry a larger model and some pack the canister sideways under the lid. Measure the canister against the pack's main compartment before the trip; a headline capacity that counts outside pockets may not leave room for one inside.
Weight limits and energy cost
Capacity and load rating are different things. REI rates its Traverse 60 for loads up to 45 lbs,5 Granite Gear rates the Crown3 60 at 25 lb without its framesheet, 35 lb with it and 43 lb with the optional aluminum stay,6 and ULA gives its 68-liter Circuit a 35 lb max load.7 A roomy pack with a modest rating can be overloaded on day one of a self-supported week, when food weight peaks.
That peak weight has a real cost. In lab measurements, walking energy rose roughly in a straight line with backpack load, by about 7.6 watts per extra kilogram,8 and a study of Appalachian Trail long-distance backpackers found packs averaged 25 to 28% of body weight.9 Planning shorter first days, while the pack is heaviest, is a simple way to manage a week-long load.
