Open main menu

Guide to Backpacks

by Alicia MacLeay
October 11, 2005

Ah, to go a-wandering with a knapsack on your back. Whether you’re setting off on a trail run or a weeklong backpacking trip, you’ll need a way to carry your gear.

How to Choose a Backpack

Like most outdoor gear, choosing a backpack depends on what you plan on doing with it primarily. Consider how long you will be gone on trips (a day, overnight, a week?), how much gear you’ll need, or want, to bring along (are you a minimalist fastpacker or deeply attached to your creature comforts?), and when you’ll be out (winter requires more and heavier gear).

Answering these questions will help you determine the first factor in selecting a backpack—capacity.

How Big?

  1. Pack sizes vary between manufacturers and capacity needs depend on the individual. However, in general the following ranges are a good starting point:

    1,800-2,500 cubic inches (30-40 liters)—for hiking trips with a daypack

    3,000-5,000 cubic inches (50-80 liters)—for overnight and multi-day backpacking trips up to a week

    More than 5,000 cubic inches (80 liters and more)—for trips longer than a week or winter overnights

  2. Choose a backpack that will fit the greatest amount of gear you’ll need to carry. Don’t forget the group gear you’ll need to bring along too.

  3. That said, don’t buy a pack that’s bigger than you need. You’ll be tempted to carry more than necessary or will end up with a floppy, half-filled pack.

  4. Depending on your range of activities you may need more than one backpack. Perhaps a large internal frame pack for multi-day backpacking trips and a small daypack for day hikes.

  5. If you’ll be carrying specialty gear like ice axes, snowshoes, or a snowboard, look for a pack with features or accessories designed to hold those items, rather than trying to jury-rig them on later.

Internal versus External

If you’ll need a medium- to large-sized backpack for your adventures, you’ll have to choose between an internal or external frame pack.

  • Internal frame backpacks are designed to carry the pack weight on the hips and with their body-hugging design provide the most balance and freedom of movement. This is especially important if you’ll be on rough trails, off-trail, scrambling, climbing, or skiing. Internal frame packs work well for nearly everyone and are the most popular option.

  • External frame backpacks were once the mainstays of backpacking. They can help you carry very heavy loads. Because they don’t lie against the body they are cooler in hot weather. They may be less expensive and can be good introductory backpacks for growing kids and beginners.

Fit and Comfort

You can select a pack with the right design, size, and features for your activities, but if it doesn’t fit comfortably you’ll regret your purchase over the long haul. Most important, your pack should be adjustable to fine-tune the fit to your individual body. While nothing beats the expertise of a knowledgeable pack fitter, below are some tips to help you choose a backpack that fits you well.

  • Size a backpack to your torso length, not your height. Don’t assume you need the tall (or the regular or the short) model just because of your height. To find your torso length, have someone measure from the iliac crest at the top of your hipbone to the prominent bone at the base of your neck (the seventh cervical vertebrae).

  • The sizes of different manufacturers' frames may correspond to different torso lengths, so check the pack’s technical specifications. For example, a 20-inch torso length may mean a regular size in one pack and a large in another.

  • Since it will be supporting your pack’s weight, make sure the hipbelt provides adequate padding. Some pack makers offer interchangeable hipbelts in different styles and in sizes for both men and women for a better individual fit.

  • During a fitting, load up the pack with weight (an amount you typically would carry) to see how well the pack carries. Then walk around with the loaded pack, practice taking it on and off, make sure you can look up without whacking your head on the pack, and climb up and down stairs.

  • Shoulder straps, which control the fit of the suspension system, should be well padded and adjustable.

  • An adjustable sternum strap, which connects the shoulder straps, helps bring the load weight forward, and off your shoulders.

  • A padded back or frame sheet will keep your stove, tent poles, and other hard objects from jabbing you in the back.

  • Women and others with short torsos, like kids, should consider backpacks sized for them. Many pack manufacturers produce women-specific or short torso versions.