Backpacking Backpacks | Buyer’s Guide For Multi-Day Trekking Packs - Outdoors Magic

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Backpacking Backpacks | Buyer’s Guide For Multi-Day Trekking Packs

Essential facts and the features to look for if you're buying a backpack for multi-day trekking or backpacking adventures

A reliable backpack is an absolute must on any multi-day adventure. It’ll be your gear-hauling workhorse, carrying everything you need to survive – tent, sleeping bag, 12 packs of ramen noodles and all the other essentials you’ve packed for your off-grid adventure. A top-quality backpack will be lightweight, supportive, durable and feature-rich. It won’t give you backache and instead it’ll fit comfortably, almost ‘floating’ along with you as you smash through the miles.

But choosing the right backpack for you can be a bit of minefield. Pick the wrong one and you’ll be rolling around on the floor like Cheryl Strayed in Wild, trying in vain to get your ridiculously humongous backpack on; or like Katz in Bill Bryson’s A Walk in the Woods, so fed up with backache that you start emptying half of your backpack’s contents over a cliff edge in a fit of rage.

To avoid a similar back-busting fate, here’s our handy buyer’s guide to choosing a backpack, whether you’re walking the West Highland Way or hostel-hopping in south-east Asia. We’ve outlined all of the key features to look out for – everything from back panel systems, shoulder padding, hipbelts and pockets – and summarised what you should expect from a high quality, supportive and comfortable backpack.

If you already know what you’re after, check out our round up of the best backpacking backpacks currently on the market, with options from the likes of Osprey, Fjällräven and Lowe Alpine. Otherwise let’s dive straight into the buyer’s guide.

An ultralight pack by Six Moon Designs. Photo: Mike Brindley
The mid-weight Airzone Pro by Lowe Alpine. Photo: Mike Brindley
Exped's Thunder 70. An example of an expedition size pack. Photo: Mike Brindley

Backpacking Backpack Types

  • Ultralight backpacks – sized between 35-50L, these ultralight backpacking backpacks are for the gram-counting ultralight enthusiasts (y’know, the type of campers who keep a colour-coded spreadsheet of their kitlist weight). Weighing around 1kg, or ideally less, these packs certainly won’t hinder your progress, and instead will make you feel light and nimble on the trail compared to most other fully-laden backpackers. Features will be minimalist, using lightweight materials, and the overall structure will be more flexible than average. Load-carrying capacity won’t be super high, but there’ll still be enough space for the pared-back essentials. These packs are best-suited to spring or summer trips, and multi-day hikes with regular re-supply opportunities. Example – Sierra Designs Flex Capacitor
  • Mid-range backpacks – probably the most common option for the UK outdoor enthusiast, a mid-range 50-60L backpack strikes a nice balance between volume and portability.  You’ll have ample room for all of your food supplies, spare clothes and camping gear, yet you won’t be so heavily-laden that it’s impossible to get through the miles. A good mid-range backpack will have a comfortable back system, weight-bearing hipbelts, handy pockets and a strong, weather-resistant design – and will weigh between 1-2kg. Example – Osprey Kestrel 58
  • Expedition backpacks – sized 60L+, these gear-hauling monsters are for the hardcore adventurers (or people who don’t mind walking very, very slowly). Backpacks in this category will offer superb support and structure, to accommodate the hefty loads, as well as cavernous interiors for a serious amount of kit. They’re best suited to anyone heading into areas of wilderness for long periods of time – when there’s little chance of resupplying and you have to carry everything you need in with you – or for winter expeditions where gear demands are far more significant. Example – Lowe Alpine Cerro Torre

Whichever backpacking backpack type you’re after, here are the main features that you need to be considering.


The volume of multi-day backpacks is measured in litres, varying from from about 35L to 65L+. Ultimately the size of backpack you need will depend on where, when and why you’re going somewhere. For multi-day expeditions in winter, where thick and warm equipment is required, a far larger backpack will be required (obviously); whereas on a summer trek with ample re-supply opportunities in towns or villages, a smaller backpack will suffice.

Sierra Designs’ Flex Capacitor. An example of a lightweight backpack that has a wide potential for volume adjustment. Photo: Mike Brindley

The problem with larger backpacks is that you’ll inevitably fill them with non-essential items, and the end result is a back-achingly hefty load. To stay light and happy on the trail, we’d recommend aspiring to the lowest volume pack suitable for your own circumstances.

Most manufacturers measure the volumes of their packs by adding up the total volumes of the main compartment, plus any lids, side pockets and hipbelt pockets.


It’s vital to pick a backpack with a size appropriate for your torso length (not your overall height). The easiest way to figure this out is to go to a store and try backpacks on, taking advice from a knowledgeable sales assistant if possible. However it’s not impossible to figure out your perfect backpack size from home. Many brands have size guides on their websites, advising in great detail how to use a tape measure to calculate you back length – “from your C7 vertebra (the bony protrusion at the back of your neck) to your iliac crest (the top of your hips)”, as one brand puts it. Osprey even have a really nifty PackSizer app, which uses your phone’s camera to digitally measure exactly which pack size you need.

Some backpacks come in various sizes, enabling you to pick the right option for your body size. Lowe Alpine packs come in small-medium, medium-large, and large-extra large versions for example. Modern packs are often adjustable too, via webbing straps, Velcro or other systems, enabling a fine-tuned fit to your exact torso length. Women and youth specific products are available too.

It’s not just about torso length, however. The other main consideration is your waist size. Hipbelts are very adjustable and should fit the majority of body shapes, but anyone particular large or thin may need to check a standard hipbelt fits their waist correctly. Ideally you want the hipbelt to wraparound your hips in a snug yet comfy way, bearing the backpack’s weight without being excessively tight.


Once you’ve decided on the volume and fit, the next consideration, and the one that you should prioritise above all else, is the comfort. The backpack is going to essentially be your home for a few days; it’s going to get heavy, it’s going to get annoying. It must be comfortable. And the only way to test that is to try it on.

The elements you need to look out for are how it fits your back. Pack it with the equipment you’ll be taking, make sure all the straps are done up – the hipbelt of course, and also the sternum strap across the chest – they all make a surprising difference to fit and weight distribution. Make sure there are no bits that poke you or have the potential to be sore, and that you feel your movement isn’t impeded.

Back System

This is where backpack tech can become rather confusing and complex, exacerbated by brands’ use of scientific-sounding gobbledygook such as a “ventilated trampoline suspended mesh back panel” or an “aluminium alloy chassis with mesh-encapsulated matrix foam”.

But let’s cut through the marketing spin. Ultimately, all backpack systems have the same goal: to transfer the load to your hips, and provide a comfy carrying experience. Osprey describe the back system as the “engine of the pack” and the “core piece of pack technology that helps determine load carrying ability, the ventilation of the pack and the comfort you’ll feel while carrying it”.

The Vaude Assumetric, an example of a simple perforated mesh foam back system. Photo: Chris Johnson

Most modern backpacks feature internal frame backpack systems. External frame systems, the type with a visible metal structure and square-ish pack shape, are very rare these days; while frameless backpacks – basically a sack with straps – are a more niche product for obsessional ultralight enthusiasts. All internal frame packs are figure-hugging and streamlined, holding the load close to the body for a stable and comfy carry, but there are differences.

Some internal frame backpack systems carry the load directly next to the body, with the back panel made from perforated foam or padding with air channels. This snug, close-to-the-body fit ensures maximum comfort and an extremely stable load distribution. But, despite the perforations or air channels, your back will probably get very sweaty. An example of this type of backpanel is Lowe Alpine’s Air Contour+ technology.

To avoid over-sweating, instead opt for a backpack with the load carried away from the body. How does this work? Mesh back panels hold the main body of the pack away from your back and allow air to pass over it, cooling and venting as it goes. This means a cooler, less sweaty back and a more efficient physiology in warm conditions, as there’s more surface area available to lose heat from.

But there are cons. The air gap means the load is carried further away from your back, which in turn makes the pack feel like its levering away from your back. To accommodate the back system, manufacturers also end up with a long, thin, sometimes curved packing space making these backpacks deceptively low in volume and awkward to pack. An example of a well-ventilated back panel is Osprey’s AirSpeed system – a “ventilated trampoline suspended mesh backpanel which creates an air space between the pack and your back”.

Load-carrying Capacity

Manufacturers often state a maximum load in kilograms a particular backpack is designed to carry. Generally speaking the larger the backpack’s volume, the more supportive the back system, and the higher the load-carrying capacity. A thickly-padded, wide hipbelt and rigid frame are essential for carrying for heavier loads.

Shoulder Straps

Shoulder straps should fit comfortably and be adjustable to your body shape. If you like to carry more of the weight on your shoulders, thicker padding in the shoulder straps is important; if you prefer to transfer most of the weight to your hips (the recommended way) shoulder strap padding is less critical.

Photo: Chris Johnson

These days nearly all backpack also feature a sternum strap at the mid-chest height, which enables lateral connection of the shoulder straps to boost comfort and stability. Another feature to look out for are load lifter straps, which adjust how close the upper part of the backpack is to your back. Tweaking these can further help ensure a bespoke, comfy fit.


All backpacks have access through the top – it’s a standard approach. This works fine, although finding items at the bottom of your pack can involve some rather frustrating rummaging. To solve this issue, some packs offer zippered access at the bottom or side of the pack.

Weather Resistance

Backpacks are rarely waterproof, although all will have some kind of water-resistant treatment and the fabric will stand up to a fair amount. Several come with external rain covers. These are of limited use in very bad wind, and we reckon it’s much better to pack your items inside dry bags or a pack liner within the backpack.


Modern backpacks often come with a myriad of different types of pockets. Zippered hipbelt pockets are handy for stashing gear you’re likely to need on-the-go, such as a snack or your mobile phone. Internal zippered pockets, often located underneath the lid, are useful for stashing keys and valuables safely, while elasticised side pockets are great for water bottles or possibly a tent or sleeping mat. Some packs also have larger mesh shovel pockets, or stuff pockets, with a stretchy expandable capacity for stashing waterproofs, rubbish and other items. Ultimately, the number, type and orientation of pockets you need comes down to what kit you’re carrying, and personal preference. There is no right or wrong answer.

Other Features

Other features to look out for in backpacks include: an internal sleeve for housing a hydration bladder, with integrated ‘portals’ for sliding the hose through; attachment points for trekking poles, sleeping mats or anything else you want to hang, clip or strap to the outside of your backpack; a removable top lid that can double as a daypack, if you’re taking on side-trips off the main trail; and separate compartments for separating wet and dry gear.


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