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.