By Dana Okoro, Editorial Reviewer · Published September 14, 2026, 6:03 PM ET · Updated September 29, 2026, 6:16 PM ET
Direct Answer
A common rule of thumb is that a loaded backpack sits at or under about 20% of the hiker's body weight for multi-day trips, with day hikers targeting closer to 10–15%. Fit and conditioning change how a given percentage feels, so treat it as a starting point rather than a limit.
In plain English
Using a percentage of your body weight is a simple way to pick a sensible pack weight. A bigger person can usually carry a bit more than a smaller person, so a percentage scales the target to you. For an overnight trip, many hikers aim for about a fifth of their body weight.
But treat that number like a speed limit sign on a road you've never driven: a guide, not a promise. Your fitness, how well your pack fits, and the trail itself all change how a load feels. A well-fitted pack on a gentle trail can feel easy. The same weight on a steep, rocky path can feel like a lot.
Kids are different. Children should carry a smaller share of their body weight than adults. Doctors' groups give their own, lower numbers for kids.
The 20%-of-body-weight figure is the most commonly cited target for a loaded multi-day pack, but it functions as a starting guideline rather than a fixed rule that applies identically to every hiker. Several factors shift where an individual hiker should sit within that range.
Trip type changes the target percentage:
Trip Type
Target % of Body Weight
Day hike
10–15%
Multi-day backpacking
~20%
Conditioning matters as much as the raw percentage. A hiker who backpacks regularly and carries a well-fitted pack tolerates a higher percentage comfortably than a beginner carrying the same relative load. Fit plays an outsized role too: a properly adjusted hipbelt is meant to carry most of a loaded pack's weight, so correct torso sizing and hipbelt adjustment let more of the load land on the hips rather than the shoulders.
Age and body type push the percentage down rather than up. Kids and youth hikers should carry meaningfully less than the adult 20% guideline, and petite or smaller-frame hikers may do better below the adult guideline even on multi-day trips, since the same percentage represents fewer total pounds of margin for fit and posture to absorb.
Percentage guidelines apply to total loaded pack weight — base weight plus food, water, and fuel — not to base weight alone. A hiker chasing a specific percentage should still track base weight separately, since it's the portion fully within their control before a trip's food and water requirements are added on top.
Lining up the numbers
The percentages on this page are common hiking guidance, but they don't come from a single study or standard. Here is what the sources actually say. A 2026 study of long-distance hikers notes the literature has suggested packs stay at 10–15% of body weight, and found forefoot pressure rose 5.41% with a pack at 10% of body weight and 8.73% at 20%, compared with no pack.1 Deuter, a pack maker, says people can carry a maximum of 20–25%.2 A 2022 review puts the adult ceiling for military, hiking and mountaineering loads at 40% of body mass.3 The US Army's ideal fighting load for conditioned soldiers is about 30%.4
Real-world data sits above the 20% target. A 2004 study found Appalachian Trail long-distance backpackers averaged 25.0% of body weight for men and 27.9% for women.5 That doesn't make those loads ideal. It means loads up to about 25%, as some guides allow for conditioned hikers, match what many experienced backpackers carry, while the lower research figures suggest there is a real cost to going heavier.
Children are a separate case
Most research on kids and backpacks comes from school bags, not hiking, but it's the best guide available. The American Academy of Pediatrics advises that a child's backpack weigh no more than 15% of body weight.6 Nemours KidsHealth gives a range of 10% to 20%,7 and the 2022 review says children's total load should not exceed 10% of body mass.3
Kids often exceed these numbers. In one study, 75% of students carried more than 10% of body weight and 17% carried more than 20%, and the authors suggested even the 20% upper bound may be too high for younger children.8 For a hiking child, starting at the low end and letting an adult carry the shared gear is the cautious approach.
Why the same percentage can feel different
A percentage treats all bodies the same way, but the energy cost of carrying a pack isn't only about the ratio. Knapik's review notes that the energy cost of walking with a backpack rises with load weight, body mass, walking speed and grade.9 That's why terrain and pace matter as much as the number on the scale.
Some guides suggest petite hikers do better nearer 15–18%, which is reasonable caution, but no source in our library tests that range. The Boulware study does show the gap in practice: women in that study carried a smaller pack in kilograms than men, 17.3 versus 19.6, yet a larger share of their body weight.5 Much of a pack's weight is gear that doesn't shrink with body size, which is why base weight is the lever smaller hikers can pull hardest.
