©istockphoto/da-kukA com­fort­able hik­ing back­pack will trans­form your hikes. A bad back­pack, how­ev­er, will great­ly lim­it your poten­tial. With all the options out there, it can be dif­fi­cult to know the dif­fer­ence between a good back­pack and a bad one. Among a huge vari­ety of shapes, styles, and sizes—how do you know which is best for you?

Back­pack Size
The first thing you need to con­sid­er is the size of the back­pack. Dif­fer­ent hik­ers have dif­fer­ent needs, and pick­ing a back­pack that is too small or large for your jour­ney means you will have to over­stuff it, or under­fill it. If you do this, the weight won’t be even­ly dis­trib­uted and the back­pack might put too much pres­sure on cer­tain parts of your back. This will become painful after an hour or so of hiking.

To com­bat this, write down every­thing you will need for your upcom­ing trek, or what you car­ry on your usu­al hikes. This should give you a good idea of how many liters your back­pack will need to be. Typ­i­cal back­pack sizes are small, medi­um, and large, and many have a range of adjusta­bil­i­ty in tor­so height and hip belt. You should con­sid­er the length of your tor­so, rather than your height when choos­ing a back­pack; if you are tall but you have a small tor­so, a medi­um back­pack will prob­a­bly fit best.

The ulti­mate goal is to find a back­pack that will have room for every­thing you need with­out being too big, cre­at­ing a poten­tial­ly over­weight pack.

Car­ry­ing Capacity
The next thing you need to con­sid­er is the car­ry­ing capac­i­ty of the back­pack and your end goals. For exam­ple, if you are trav­el­ing on planes or bus­es with the pack, you’ll want to make sure that it can fit in over­head compartments.

The length of your trip is the main thing to con­sid­er when it comes to car­ry­ing capac­i­ty. If you are plan­ning hik­ing trips that will last for more than one day, you will need an overnight back­pack with at least a 35-liter range. Mul­ti-day packs typ­i­cal­ly range around 45 liters up to 70 liters. This will have enough room for water, hik­ing gear and over­sight pro­vi­sions. How­ev­er, if you only plan hik­ing trips that last a few hours, a small­er back­pack will be just fine (15 liters or 22 liters are com­mon sizes for day hikes).

Once you have worked out the best size and vol­ume for your back­pack, you can start to think about the back­pack sus­pen­sion sys­tem. Hik­ing packs are fair­ly heavy, so it’s impor­tant to find a back­pack that spreads the weight around your body even­ly, with no pres­sure points. If you buy a bag that has no sus­pen­sion, your shoul­ders will car­ry all the weight and with­in a few hours, you will be in pain.

The ide­al hik­ing back­pack will come with a decent hip belt, chest or ster­num strap, and shoul­der straps. This secures the pack to your body so you don’t feel the weight as much. It also means you can move around freely with­out wor­ry­ing about your back­pack falling off or com­ing loose.

It is best to choose back­packs that have thick, padded shoul­der straps that will dig into your shoul­ders less, and the thick­ness of the straps will help to dis­trib­ute the weight even­ly across your shoulders.

Do your home­work and spend some time try­ing on packs before mak­ing your purchase.