How to choose a backpacking backpack: volume, fit and carrying a real load

Backpacking packs are sized in litres, and the useful range is roughly 50 to 75 litres. A 50–60 litre pack suits most weekend and summer trips for someone who packs reasonably light. A 65–75 litre pack is the range for multi-day trips, colder weather with bulkier insulation, or a shared load where one person carries the tent and the other carries food and fuel.

Bigger is not better. A pack that is too large invites you to fill it, and a heavy pack is heavy regardless of how well it fits. Aim for the smallest volume that fits your gear plus a little room for group gear or extra food. If you usually carry a bear canister or winter gear, size toward the top of the range.

Like daypacks, backpacking packs are sized by torso length — the distance from the bony bump at the base of your neck to the top of your hip bones. Two people of the same height often need different pack sizes. Measure yourself or get measured at a shop; do not assume your height maps to a size.

The hip belt is what carries the load on a backpacking pack — 70 to 80 percent of the weight should sit on your hips, with the shoulder straps only stabilizing the pack against your back. A well-fit hip belt wraps the iliac crest and cups the hips; a belt that rides on the waist or on the ribs will dig in within an hour. Many packs offer interchangeable belt sizes or adjustable harnesses, which is worth insisting on if you are between sizes.

Modern backpacking packs use internal frames — aluminum or carbon stays that transfer weight to the hip belt and hold the load close to your back. A single vertical stay is fine for loads under 35 pounds; a perimeter frame or dual stays handle heavier loads better and keep the pack from sagging.

Frameless packs are for ultralight hikers carrying under 20 pounds total — they rely on a sleeping pad folded inside for structure and save weight at the cost of load-hauling ability. External-frame packs are rare now but still suit heavy, awkward loads over long distances; for most backpackers an internal frame is the right call.

Top-loading packs are the most common and the most weather-resistant — a single lid closes the main compartment and rain runs off it. The downside is reaching gear buried at the bottom; most top-loaders add a bottom sleeping bag compartment with its own zipper. Panel-loading (front-zip) packs open like a suitcase so you can reach anything, which is convenient at camp but slightly less weatherproof and a bit heavier.

For most backpackers a top-loader with a bottom compartment and one or two side access zippers is the sweet spot. The bottom compartment keeps the sleep system separate, and side zips let you grab a layer without unpacking everything. Decide based on how organized you like to be at camp versus how much you value simple weatherproof closure.

A padded, well-shaped hip belt is the single feature worth paying for on a backpacking pack. The belt should cup the hips and sit on the iliac crest, not the waist. Stiff foam that breaks in over a few trips is better than soft foam that bottoms out under load. Belt pockets for snacks and a phone sound trivial but you will use them daily.

Load lifter straps run from the top of the shoulder straps to the pack frame and pull the load toward your back, improving balance on steep or rough ground. Set them at roughly a 45-degree angle when the pack is loaded. A sternum strap across the chest keeps the shoulder straps from sliding outward; adjust it to comfort, not tight.

A suspended mesh back panel keeps the pack off your back so air flows and sweat dries — a real comfort gain on warm trips, at a small weight cost. A traditional foam-and-frame back panel is more durable and transfers heavy loads better but runs hotter. Pick suspended mesh for three-season comfort, solid panel for heavy loads and durability.

Most packs are water-resistant, not waterproof. Use a pack liner (a trash compactor bag works) or a rain cover for real weather. Hydration is usually a bladder sleeve with a hose port, side bottle pockets, or both — side pockets that fit a standard one-litre bottle securely and let you reach it while wearing the pack are the feature you will appreciate most.

Worth it: a removable lid that converts to a daypack, a sleeping bag compartment, a hydration sleeve with a port, dual ice-axe or trekking-pole loops, and a rain cover or included liner. These define how usable the pack is over years of trips.

Skip: excessive external pockets and daisy chains that snag on brush, dedicated compartments for gear you do not own, and heavy detachable daypacks that add weight you never use. A heavy pack is heavy before you add anything to it — check the empty weight and favour packs under 4 pounds for typical three-season use.

Load the pack with 15 to 20 kg — use your actual gear plus water bottles or books to reach a realistic weight — then put it on and loosen all straps. Buckle the hip belt, cinch it to sit on the iliac crest, snug the shoulder straps, and set the load lifters. Walk for ten minutes including stairs and a hill.

Pressure points appear under load, not on an empty shop floor. If the shoulders ache within ten minutes the belt is too low, too loose, or the torso length is wrong. Once the fit is right, note the strap settings so you can return to them after the pack is unloaded or adjusted by someone else.

For weekend and summer backpacking: a 55–60 litre internal-frame pack with a good hip belt, a bottom compartment, and a suspended mesh back panel — comfort and ventilation over raw capacity. For multi-day and shoulder-season trips: a 65–75 litre pack with dual stays for heavier food and insulation loads, and a solid back panel for durability.

For ultralight thru-hikers carrying under 20 pounds total: a frameless or minimal-frame pack in the 40–50 litre range, sized to your gear, not to a volume target. For group trips where you carry the tent and partner carries food: size toward the top of the range so the shared load actually fits.