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How to fit a backpack: sizing guide

When choosing and fitting a pack, the first thing to consider is how much capacity you want. Carrying a pack that’s bigger than you need means you’ll be carrying extra weight. Ideally your pack should be big enough to fit all your gear inside except for the items you intentionally choose to attach to the exterior.

Types of packs

Look at the pack wall in any MEC store and you’ll see there are dozens of styles to choose from. Some are designed for specific activities like mountain biking or trail running, some are more versatile and will adapt to different adventures. Think of how you’ll use the pack most often, and if you’ll need it to function for one activity or many.


Hiker with a blue backpack outside on a sunny day

These little workhorse packs are designed for your everyday carry or for hikes and activities that last a few hours, but less than a day. Unless they’re an ultralight model designed to stash in a pocket or inside another pack, they usually have a lightly padded backpanel, and no rigid internal frame. They are best for carrying loads less than 10kg, as the weight is supported by your shoulders rather than your hips.

Choosing a daypack:

  • Mesh or venting channels down the back to help keep you cool
  • Waist strap to prevent the pack from bouncing or shifting, for this size it won’t need to bear weight
  • Hydration sleeves and ports if you plan to use a hydration system
  • 10–25L capacity

Backpacking and expeditions

Hiker with large backpack walking on a trail

Sized for multi-day adventures, these packs are designed to carry heavy loads comfortably. A side zipper or a separate compartment for a sleeping bag is handy, so you don’t have to unpack all your stuff to find just one item. Some packs come with detachable side pockets or a removable top lid you can leave at home if you don’t need the extra capacity for a trip.

Choosing a backpacking pack

  • Substantial internal frame to support weight
  • Well-padded, adjustable hipbelt, shoulder straps, and back panel
  • An exterior pocket to store wet gear
  • Top, side and bottom access
  • Straps on the outside for attaching gear
  • 55–70L for backpacking and up to 100L for expeditions

Travel packs

For destinations where wheeled luggage won’t work, a travel pack might be perfect. Built like a backpack, they usually have a cover or zippered panel to tuck away the straps, belts and buckles so they don’t get snagged in a luggage carousel or broken during transit. A detachable daypack is often a feature. It gives you a small pack to use for day trips, to use as your carry-on bag and provides some extra capacity to bring home souvenirs.

Choosing a travel pack

  • Internal frame to support weight
  • Padded hipbelt, shoulder straps and back
  • Detachable daypack or lid
  • Pocket or panel to cover shoulder straps and hipbelt
  • Main pack or detachable pack is sized to meet carry-on restrictions
  • Internal organizers to keep clothing and shoes arranged
  • 45–75L capacity

Climbing or cragging

Most climbing packs have some padding to support the weight of ropes and gear you carry on the approach to a route. Those made to carry while you climb are usually designed to sit high on your back so they don’t get in the way when you’re clipping gear on the rear loops of your harness. They ride close to your spine to keep the weight centered and balanced. The designs are usually minimal, without external features that could snag on rock features as you climb.

Choosing a climbing pack

  • For climbing, tough fabric, few external pockets, and gear loops on the hipbelt for fast racking
  • For cragging, padded backpanel, shoulder straps, and hipbelt
  • Mesh or venting channels down the back
  • Large main compartment to hold lots of gear
  • Straps to carry a coiled rope on the outside or under the lid
  • Loops for ice axes, helmet or extra gear
  • 30–50L capacity

Mountain biking and riding

Biking packs are usually daypack-sized, but have special compartments to stash your tools, helmet and armour. Look for a pack that stays close to your body when you’re in the ride position. The hipbelt shouldn’t move upward so it digs into your gut. And you should be able to adjust the pack so it doesn’t shift or bounce when you ride uneven terrain. Some packs include a hydration reservoir. If you plan to use your own reservoir, make sure it fits in the sleeve and that the openings and ports are compatible.

Choosing a bike pack

  • Waist strap and sternum strap to keep the pack balanced
  • Lightly padded shoulder straps and backpanel
  • Hydration sleeves and ports
  • Dedicated tool pocket
  • Straps to lash helmet and armour
  • 10–25L capacity

Ski touring, snowboarding and snowshoeing

For winter conditions and for carrying safety gear, a touring pack should have a supportive frame, a system to give you fast access to your shovel and probe, plus plenty of room for your warm layers. If you expect to carry your skis or board on the outside of your pack, it’s useful to have some options. An A-frame style carry for skis keeps your pack balanced, but the extra height can be annoying if you’re under low-clearance trees or rocks. On steep terrain, the tails of your skis can drag in the snow, and it might be a better option to rig them diagonally.

Choosing a snowsports pack

  • Internal frame with padded hip belt, shoulder straps and backpanel
  • External straps to carry skis, snowboard or snowhoes
  • Fast access to your avalanche gear
  • Pockets or straps for shovel handle and poles
  • A place to stash wet skins
  • Side access for convenience and to keep shoulder straps off the snow
  • 35–55L capacity

How to fit a backpack

Most large-capacity packs come in different sizes to suit different body shapes. Look for a “back length” or “torso length” measurement when you’re shopping for a pack. It’s a better indication of how the pack will fit than your overall height. No matter how large the pack, if it’s correctly sized and adjusted, it should feel like an extension of your own body.

Measure your back length

  1. Find the most prominent vertebrae in your neck, at about the same level as the top of your shoulders.
  2. Find the top of your hipbone and trace a line around to the middle of your back.
  3. Measure the distance between these two points, this is your back length.

Put about 8–10kg of stuff in the pack and loosen all of the straps. Remember to loosen the stabilizer straps at the top of the shoulder straps too.

Adjust and fit the pack

  1. The hipbelt should entirely cover your hipbones. Some packs allow you to raise or lower the placement of the belt.
  2. Tighten the hipbelt so it’s snug but doesn’t restrict your breathing. Make sure it doesn’t shift up or drop below your hipbones.
  3. Pull down on the shoulder strap adjustments until they are comfortably snug. The straps should lie flat without bunching. They should lie flat against your shoulders, without touching your neck and without a large gap between the top of your shoulder and the strap.
  4. Slowly snug the top stabilizer straps. Pull them until you start to feel a hint of weight on your shoulders.
  5. Fasten the sternum strap that connects the shoulder straps and adjust it so your chest can expand naturally.
  6. If there are stabilizer straps on the hipbelt, snug those for comfort.

Walk around and lean forward and back to see if the weight feels balanced. Try to adjust any points that are causing pressure or are rubbing against your skin.

Care and repair

Repairing and storing your pack properly will go a long way to making it last. Make sure it’s dry before you put it away and keep it out of direct sunlight. You can use an old toothbrush to clean dirt out of the zippers before you put it away. If the zippers feel sticky and are not sliding smoothly, try rubbing a candle over the teeth and sliders to lubricate them.

Buckles are easy to replace. Consider getting some spares and carrying one with you when hiking or skiing. A functioning buckle is crucial for a comfortable trip.