Ask yourself five key questions before buying a new pack.
1. How much cargo capacity? This depends on the length and conditions of your trips, of course, and personal preferences (ultralight or ultraluxe?). As a general rule, choose a pack that accommodates your largest load, as it’s easier to compress a too-big pack than to overload a too-small one.
2. What type of pack? If your load often exceeds 40 pounds, choose a standard internal frame, constructed with a rigid suspension and durable, higher-denier fabrics. Expect the pack alone to weigh about four pounds. Lightweight packs with thinner padding and streamlined pockets are ideal for weekend loads under 40 pounds. If your base weight is 15 pounds or less, consider a true ultralight pack (less than two pounds) with thin aluminum stays or no frame structure at all (a rucksack).
3. What’s your size? Short people can have long torsos—and vice versa—so measure your back and check specific brands’ sizing. Generally, if your torso is shorter than 16 inches, try an extra small; 16 to 18 inches is small; 18 to 20 inches is medium; 20 or more inches is large. Many brands also offer interchangeable, sized hipbelts.
4. What features? Are you an organizer or a minimalist? Identify the extras you absolutely need—water bottle holsters, external gear attachments, shove-it or hipbelt pockets, ski loops, extendable lid—and don’t waver.
5. Does it really fit? Packs are like shoes: Even the right size might not be a perfect fit for your body type or shape, so test it thoroughly in the store.
>> Loosen all straps, then throw on the pack (loaded with about 20 pounds).
>> Buckle and cinch the hipbelt. Padding should be centered over the hipbones.
>> Tighten the shoulder straps, load lifters, sternum strap, and hip stabilizers (in that order). Now walk around and evaluate the fit: Does the lumbar pad sit snugly in the small of your back? Do the shoulder straps wrap over your shoulders with no visible gaps? Can you distribute the weight evenly between your shoulders and hips, with no rubbing or pressure points?
To get the best fit, try on multiple packs so you can feel the differences between a variety of brands and models. Also ask about swapping components (like putting a medium hipbelt on a large pack) to help dial in the fit. When you’ve settled on a couple of favorites, pack them: Bring your own gear to the store (or borrow equipment from the store shelves) to double-check the pack’s cargo capacity and make sure it feels good fully-loaded.
Web shopping is especially tricky if you can’t try the pack on first. If you’re unsure about your exact size, choose a model that can be modified (with an adjustable suspension and interchangeable hipbelts) and read user reviews for hints about manufacturer sizing. Another option: Limit online buying to daypacks and overnight bags, where loads are smaller and a less exact fit will suffice. Shop outfitters, guide programs, and rental shops in the fall—many dump used rental gear then (our favorite: whittakermountaineering.com).