You guessed it: a backpack is the most essential piece of equipment for backpacking. All your belongings should fit in it, and if you choose a proper one you’ll be comfortable the entire time. Different hikers have different needs; a solo 1-day hike can’t compare to couples’ overnight hiking, and when kids enter the picture it can become interesting if you’re not prepared well. 

Knowing the different types of packs can help narrow the choices and ease your shopping journey. This guide offers a comprehensive breakdown of the most common options, along with the most important factors to consider when choosing a hiking pack type, including backpack capacity, features and fit.

Types of Hiking Backpacks

Frameless, internal-frame and external-frame backpacks are the three types of hiking packs. Here is a brief explanation of each variety.

Frameless Backpacks

Ideal for lightweight loads, frameless hiking packs have adaptable construction and flexible design. Because of that and because they don’t include “heavy” plastic framesheets or aluminium rods, they’re incredibly light. With a 40-litre capacity, a top-notch frameless backpack can weigh as little as 600 grams. 

Because a sturdy design is necessary, frameless backpacks have the drawback of ineffectively transferring weight from the shoulders to the hips (via the hip belt). As a result, they aren’t appropriate for transporting large objects, and they usually have a 40-litre capacity. However, frameless backpacks are ideal for day treks and quick, light alpine ascents because of their low weight.

Internal-frame Backpacks

Ideal for light to heavy loads, packs with an internal frame have semi-rigid or rigid construction and light to mid-weight. The flat aluminium rods or plastic framesheets used in internal-frame backpacks run vertically beneath the backpack’s back panel and keep the backpack from collapsing, giving them a rigid or semi-rigid design. This design supports the hips by engaging more muscle groups than the shoulders, and the stiff structure transmits the backpack’s weight from the shoulders to the hips via the hip belt efficiently, improving your performance. 

Internal-frame backpacks are generally heavier than frameless backpacks because of the solid framework, which adds weight to the bag. However, some internal-frame backpacks have detachable framesheets or rods that allow you to reduce the backpack’s weight if rigidity is not needed – for example, when carrying light objects. Internal-frame backpacks make up the majority of backpacks with a capacity exceeding 40 litres.

External-frame Backpacks

Ideal for (very) heavy loads, backpacks with an external frame have rigid construction and heavy weight. A pack, an aluminium frame, and a harness (shoulder straps and a hip belt) make up an external-frame backpack. To ensure adequate load support, the aluminium frame is rigid. They’re less used for hiking since they’re thicker, heavier, and less portable than the other two varieties.

An external-frame backpack with a 50-litre capacity usually weighs more than 2000 grams, which is a significant increase in weight due to the massive and sturdy aluminium frame. External-frame backpacks have the advantage of typically having highly adjustable harnesses that fit both teens and tall adults. 

Additionally, you can usually easily swap out the pack for a larger or smaller one without having to alter the frame or harness. Carrying things of odd size is a common usage for external-frame backpacks; you can quickly attach a variety of bulky items to the frame using a rope or bungee cord.

What to Consider When Choosing a Hiking Pack?

Three things to look for in a hiking pack are volume (or capacity), features and fit.

Volume (Capacity)

The majority of packs include their stated capacity in their name. The ideal pack size is as compact as your intended backpacking excursions will permit. Packs that are too large will increase bulk and weight, which could make hiking difficult. Like everything “backpacking,” keep in mind the classic thru-hiker proverb: Ounces make pounds, and pounds make pain. Picking based on the days gives you the following options:

• 1-3 days. Generally speaking, you can get away with smaller hiking packs of between 30 and 50 litres for one to three nights out. These kinds of packs may easily include hiking gear necessities like food and drink for a few days, a change of clothes, a sleep system, and a few layers. Fitting your equipment into a pack this compact takes some self-control, but it can also serve as an excellent safeguard against overpacking.
• 3-5 days. Try to pack between 50 and 80 litres for multi-day excursions or shorter vacations where you want to purposefully pack a bit more luxuriantly. This is the most adaptable choice and offers you a little more wriggle room (literally).
• 5+ days. You’ll need at least 70 litres for gonzo epics. In addition to fitting the most equipment, these packs often have the strongest suspension systems, built to support loads weighing more than fifty pounds.

Features

• Ventilation. Certain features of some packs promote airflow between your body and the bag. If you frequently find yourself with a sweaty back when hiking, you might want to look into a pack with a suspended mesh back panel. This type of accessory functions similarly to a trampoline and lies between your body and the back panel of your bag to let air flow through. 
• Organization. Depending on your preferences, you may or may not desire the following organizational features: a sleeping bag compartment, hydration sleeve, bottle holders, hipbelt pockets, trekking pole attachments, adjustable back panel, and top lid pocket (sometimes referred to as a pack’s “brain”).
• Padding. Generally speaking, a lighter pack has less cushioning. If you choose a lightweight bag, you should pack as light as possible because this will result in less comfort over long hauls. If cushioning is more important to you, go for an item that has—you guessed it—more cushioning. 

Fit

Knowing the length of your torso and hip circumference is crucial because most packs come in several sizes and variants to fit a range of body types. To get it correctly, you have to learn how to measure both. Certain packs are available in extended sizes, which increase hip and waist circumference by inches.