How To Fit A Backpack

At Footsloggers, we take pack fitting just as seriously as we do our boot fitting service.  Our staff walks the talk, and many of us have been fitting packs for more than a decade.  We have more than one staff member that has thru-hiked the Appalachian Trail, and most of our staff has been on several extended backpacking adventures.

We rarely have a customer that we cannot fit perfectly.  In order to fit a pack, however, one must begin with a few basic measurements.  After that, the best pack for you can be determined when we take into consideration body type.  We prefer the opportunity to custom-fit packs in our stores, but if you don’t live nearby, we feel confident we can walk you through the process.

Differences between a Men’s/Unisex pack and a Women’s specific pack:

There are generally only a few differences, actually.  The shoulder straps will have a more narrow cut (since women’s shoulders are not usually as broad as men’s), and the straps will “flare out” more aggressively to the outside, to be out of the way of the chest.  Most women’s packs will also have a belt that is angled a bit more on the sides to fit the curvature of a woman’s hips more appropriately.  Not all women fit best into a women’s specific pack.  This depends on body type.  Likewise, some smaller-framed men, or younger guys may fit better into a women’s fit pack.

What volume size do I choose?

The longer distances you hike, the less you want to carry.  The idea is: “If I’m going camping for 2 nights…why not carry a heavy load and eat steak and take a good beverage of choice for camp?  If I am hiking for 5 or more days…those luxuries are not important: the efficiency of how my load carries becomes priority.”  If you are traveling, it is wise to go larger than smaller to make sure you are not carrying items in your hands.  You bought a pack to carry your stuff…why not make sure it has the capacity to make sure it will carry everything you might want to have with you?

A generalization can be made:

If you are hiking on weekends and maybe a 4-5 day trip as life allows, then 60-80 liters (3,500-5,000 cubic inches) should likely be the target capacity.  If you are mountaineering and carrying camping gear plus climbing gear, then look at packs 80-95 liters (5,000-6,000 cubic inches).  If you are hiking long-distance and don’t have to deal with much severe weather, look at packs 70 liters or smaller (4,500 cubic inches or smaller).

Measurements needed:

-Torso length in inches
To gather this information, it is easiest if someone can measure your torso for you.  The torso measure is the length between the C7 (cervical #7) vertebra at the base of the neck, down to the small of the back in your lumbar, in line with the iliac crest of the hip.  If you lean your head forward, the most prominent vertebra at the base of the neck is the C7.  On the side of your hips, you can feel a bump.  For women, this iliac crest bump is usually oriented a bit forward on the hips; for guys it is usually directly on the side of the hip.  We’re not looking for the top of the hip bone; rather, we need to find the outside of the side of the hipbone.  If you place your forefinger on either iliac crest, and point your thumbs at one another to the small of your back, your helper can measure from the C7 down to the spot you’re pointing to with your thumbs.

-Waist measurement in inches
This one’s easy…What is your waist size?

-Do you have a broad chest or shoulders?
Some packs offer shoulder harness straps that can be swapped for different sizes.  If you have a broad chest, it is sometimes best to go up a size in shoulder harness so that you get a proper wrap of the strap over and around each shoulder.

I have my measurements…now what?

If your torso length is less than 18”, you likely will need a small frame size pack.  If your torso length is 18”-20”, you will likely need a medium frame size.  If your torso length is over 20”, you will likely want a large frame size.

Not all packs are offered in Small/Medium/Large, so refer to the company’s specs to find out which should fit your torso best.  If you are in-between sizes, go with the larger option.  It is always better to have a pack fit slightly large than small.  The goal: to have your hips support and carry the weight of the backpack, while your shoulders stabilize the load from shifting around much.

No, it’s not yet time for a final decision!  Your waist size must be taken into consideration as well.  If your waist is smaller than 28”, you likely will need an extra small belt.  If your waist is 27”-31”, you likely will need a size small belt.  If your wais it 30”-34”, you will likely need a medium size belt.  If your waist is 33”-36”, you will want a size large belt.  If your waist is over 36”, you will need an extra large belt.

Not all packs are offered with options for belts size, so refer to the company’s specs to find out which should fit your waist size best.  It is extremely important to find a pack with a good fit in the belt in order for the rest of the pack to carry well.  The belt is the #1 most important part of a pack!

Osprey packs are some of our favorites because we are able to custom-fit anyone.  Their Aether (M’s) and Ariel (W’s) series, and their Argon (M’s) and Xenon (W’s) series both offer 100% custom fit options.  Choose the volume size you like.  Choose the color that you prefer.  Choose the frame size that fits your torso.  Choose the shoulder harness that will work best for your body type.  Choose the belt size that fits you best.  Once you have your custom-ordered pack in hand, adjust the torso frame sheet to reflect the ‘good fit’ photos below.  The last feature that makes Osprey packs superior in fit is the fact that you can custom-mold the belt on these series of packs to your hips!  There is no other pack company that offers this very important feature.  The only catch: you need to visit us (or another Osprey dealer equipped with the Osprey oven) to mold that belt!  The belt will self-mold over time, however, if this is not an option for you.

Granite Gear, Deuter, and Black Diamond are three other companies that also make some excellent options.  Of these, Granite Gear is the most custom-fit-able, followed by Black Diamond and Deuter.

I have my pack, now what?

Your pack fits according to where the belt is located.  So, it is important to get your belt situated on the right spot prior to adjusting the rest of the pack.  Make sure all straps are loosened…the belt, the shoulder straps, and the load lifter straps (located at the top of the shoulder straps).  Your belt should wrap around your iliac crest so that it is in the vertical middle of the belt.  Snug down your belt tightly once you have the belt in the right spot.  Once tightened, you should have between 3” and 5” between the ends of the padding of the belt under your stomach.  If not, then you may need a different size belt.

Now look at the shoulder straps in a mirror from the side.  There is a “hinge” where the shoulder strap leaves the frame and begins to hinge away from the pack and over/around your shoulders.  This “hinge” should be around 1”-1.5” below the top of your shoulder.  If you have a pack with an adjustable torso fit, shorten or lengthen the torso until this is in the correct spot.  Once it is positioned, pull down and then back to snug your shoulder straps.  An indication of proper shoulder harness fit: once the torso has been adjusted and you have them snug, you should have 5” or more of “tail” below your armpit when your arm is held out.

Once the belt is correct and the torso frame and shoulder harness are adjusted and snug, the next step is to follow your hand up your shoulder strap to find the load lifter strap at the top near the pack.  Pull the load lifter strap forward until you feel the load secure against your back.

Last step: Load some weight into the pack and make sure it fits comfortably.  Again, the goal is for your hips to support and carry the weight, while your shoulders stabilize the load from shifting.

Tip: To adjust the pack so that no weight is on your shoulders: Loosen your should straps from the bottom just a bit.  Now tighten the load lifters more.  You should notice a gap above your shoulders, while there is more contact and pressure on your chest.

Tip: To adjust the pack so that no weight is on your hips: Loosen your load lifter straps.  Now tighten the shoulder straps until comfortably snug.  Now pull the load lifters so that they are just tight…don’t crank them down.  Loosen the belt, and you will notice an even weight distribution across your shoulders, while the hips are free.

Tip: You will need a pack cover if your pack does not come with one integrated.  A pack cover protects from moisture, but it is also a great theft deterrent when you are traveling and worrying about your pockets being explored.  If you are between sizes on pack cover sizing, it is safer to go up in size, in case you carry anything on the outside of your pack (for example, a sleeping pad).