"Technically you only need two pieces of whatever you wear," declared one traveler planning indefinite South America backpacking. This radical minimalism—30L for months or years—sparks fierce debate.
The Ultralight Argument
Expert Andy Sparks told Outside Magazine: "The sweet spot for long-term travel is 30-35 liters—enough for essentials, small enough to never burden."
What Actually Fits
One traveler's Osprey Daylite 26+6 held: 4 t-shirts, 2 shorts, 6 underwear/socks, rain jacket, full electronics (2 phones, chargers, watch), complete toiletries, first aid kit, and Hoka hiking shoes.
Key enablers: packing cubes for compression, ultralight quantities, and ruthless "if unused in a week, ship home" policy.
The Counter-Argument
"Two of everything works until it doesn't," one commenter noted. Climate variation from Patagonia winter to Amazon heat requires layering that fills 30L fast.
The 40L Compromise
Tortuga's guide recommends 40-45L for indefinite travel: "The difference between 30L and 40L is the difference between making it work and being comfortable."
The philosophical divide: Is your pack an optimization problem to solve, or a tool that should make travel easier? Both are valid approaches.

