In plain English
Five days on the trail without a store means carrying everything: your shelter, your sleeping bag, your stove, clothes for changing weather, and five days of food. Food is the part that grows with every extra day, so a five-day trip needs a noticeably bigger pack than a weekend.
Most people end up with a pack of about 55 to 65 liters. If your gear is light and packs small, you may fit in less. If you carry a bulky sleeping bag or warm winter clothes, you may need more.
A useful habit is to lay everything out on the floor before you buy or pack. Put the food for all five days in one pile. Seeing it all at once shows you how much space you really need, far better than any rule of thumb, and it often reveals things you can leave at home.
A five-day hike without resupply falls in the extended-trip capacity range, generally 55–65L. That range accounts for roughly five days of food, a full shelter and sleep system, and enough clothing to handle a stretch of variable weather without restocking.
A simple planning formula: budget roughly 10–15L per night of food and consumables on top of a 15–20L base for shelter, sleep system and cook kit. For five nights, that lands between 65L and 95L using the high end of the formula, but most hikers with a reasonably efficient three-season kit land closer to 55–65L in practice because food compresses well and doesn't scale linearly with a rigid per-night estimate.
Gear choices shift this range meaningfully. A hard-sided bear canister — required in some US wilderness areas — takes up fixed space regardless of how much food is inside it, and a typical canister adds roughly 9 liters of fixed volume. An ultralight setup with a quilt, trekking-pole shelter and dehydrated meals can bring a five-day trip down into a 45–50L pack, while a hiker carrying a synthetic sleeping bag, a canister stove system and full cold-weather layers may need closer to 70L for the same five nights.
Food planning also matters more on a five-day trip than on a weekend, since it's long enough that meal-by-meal bulk adds up noticeably. Dehydrated or freeze-dried meals pack significantly smaller than fresh or canned food for the same calorie count, and repackaging food out of bulky retail packaging into resealable bags is a simple way to reclaim a liter or two of pack space without changing what's actually being carried.
The page offers a formula of 10 to 15 liters per night on top of a 15 to 20 liter base, and notes it gives 65 to 95 liters for five nights while most hikers land nearer 55 to 65. That formula is a rule of thumb without a published source, and its own arithmetic shows the weakness: food does not take a fixed space per night, and much of a base kit compresses. The Washington Trails Association's simpler bands put three to seven nights at 50 to 70 liters.1 Use the formula's answer as an upper bound rather than a target.
Brand positioning shows how fuzzy the lines are. Kelty positions its 65-liter Asher for two to three days in the backcountry,2 while Osprey describes its Atmos AG 65 as built for heavyweight weekends or week-long trips.3 The same volume stretches across very different trip lengths depending on the gear assumed.
Five days and the bear canister
Five days sits right at the edge of what compact canisters hold. Denali's small container weighs 3 pounds and holds three to five days of food for one person, while its larger one weighs 5 pounds and carries seven to ten days.4 New York's DEC describes typical canisters as about 8 by 12 inches, holding up to five days of food.5 Glacier Bay's 560-cubic-inch loaner, about 9 liters, holds roughly six days.6 A big appetite or bulky food can tip a five-day trip into the larger size, which then fixes an even bigger rigid block inside the pack. Where canisters are required varies by park, area and season, so check the current rules for your route.
Food and water: volume versus weight
There is no official calorie figure for backpacking. The best-known numbers, 3,400 to 4,300 kcal a day, come from military research on cold-weather operations,7 so treat them as a cold-weather reference rather than a general target. Dry, energy-dense food saves both volume and weight. Freeze-drying removes up to 98% of the moisture from food,8 which is why freeze-dried meals pack so small compared with fresh food.
Water is dense and cannot be compressed. A liter has a mass of about a kilogram.9 At Guadalupe Mountains, where the National Park Service advises a gallon per person per day, a three-day, two-night trip means about 24 pounds of water.10 On a dry five-day route, the longest water carry rather than the food can decide your pack size.
