How to Choose a Backpack | Backpack Buying Guide

Backpack size guide
How to choose a backpack.

Most adventures begin with packing a backpack, but with so many options, how do you know which pack to choose?

Explore this guide to help you decide on which backpack is right for you. 

What size backpack do I need?

Here is a rough guide to help you choose how much volume you might need. 

Activity Duration or distance Capacity
Running Short distance 3-6 L
Running Long distance 6-12 L
Fast hiking / running Multi-day 18-30 L
Hiking Day hikes 18-40 L
Hiking Multi-day 35-50 L
Climbing / mountaineering Day 20-50 L
Skiing Day 20-30 L
Ski touring Multi-day 30-45 L
Trekking Multi-day 40-60 L
Trekking Multi-day remote 60-120 L

A note on the seasons.

The size of pack you need is influenced by many factors like what kit you will need and how long you’re out there for, but it’s also important to consider when and where you are going.  For example, when buying a hiking backpack, you won’t need quite so many layers for day hikes in a hot country as you might for winter walks in a cold one. Remember to choose the volume of pack accordingly. 

Front of the pack.

Access 

Top loader packs are great for stuffing all your gear inside, but zipped side access or even back panel access allows you to reach key kit without unloading. 

  

Extendable and removable lids 

Ideal for carrying extra kit or stripping off when weight is critical. 

  

Stash pockets 

For easy access to accessories, snacks, or layers on the move.  

  

Gear loops and attachment points 

For carrying walking or running poles, ropes, ice axes, helmets, and trad gear, depending on your style of ascent. 

  

External compression straps 

To secure your kit inside the pack and keep it closer to your body, giving you better freedom of movement.   

  

Bungee cords 

Great for lashing layers or extra kit to the outside of your pack when you’re on the move.  

Back of the pack.

Shoulder straps 

Built with breathable fabrics and additional padding depending on the weight of your load. 

  

Load lifters 

Bring the weight of the pack closer to your body and onto your hips to take the strain off your shoulders. They’re also great for stabilising the load when you’re walking downhill, as you can loosen them to help balance the weight.  

 

Chest strap 

Helps to keep the shoulder straps in place and prevent them sliding off your shoulders (double chest straps are ideal if you’re moving quickly as they help stabilise the whole pack and reduce bounce). 

  

Back panel 

Rigid, padded, moulded or flexible – this will depend on how much weight you’re carrying. 

  

Back ventilation 

From breathable fabrics and air vents to fully suspended mesh systems, there are different levels of ventilation available to stop you getting sweaty.  

  

Hipbelt 

Critical when you’re carrying heavy loads, your hipbelt ensures the weight of the pack is transferred to your largest muscle groups such as your legs and glutes, with additional padding for comfort and pockets for keeping essentials handy. 

  

Inside the pack.

Compartments 

Great for organising your gear especially on long trips with lots of different kit. 

  

Hydration compatibility 

Features an internal pocket for the water bladder, hole at the top of the pack for the tube, and fabric loops on the straps to keep it secure. 

  

Zipped pockets 

Ideal for securing valuables and small equipment. Great for travelling and trips with lots of kit. 

Two people trekking up a mountain wearing day hiking packs.
Day hiking backpacks.
You need a comfortable pack that can carry reasonably heavy loads, while allowing you to move freely up tough trails. 

Key features for day hiking backpacks:  

  • Tough, lightweight and weather-resistant fabrics to deal with all weather and regular use. 

  • Strong but flexible back panel for complete mobility. 

  • Stay cool with back panel venting or suspended mesh systems. 

  • Cinch the pack in with compression straps, great for lighter days when you’ve got less to carry. 

A man walking through jungle terrain wearing a Rab trekking pack.
Backpacking and trekking backpacks.
You need a highly comfortable pack that’s adapted to carry heavy loads and keep your gear organised.  

Key features for trekking backpacks: 

  • Reinforced fabrics stand up to prolonged use on tough terrain. 

  • Stay comfortable with ventilated back systems featuring foam cushioning. 

  • Internal dividers and sections to separate your gear. 

  • External attachment points for walking poles and extra kit. 

Two climbers on a mountains wearing Rab gear and climbing packs.
Climbing and mountaineering backpacks.
You need a pack that balances low weight with durability and freedom to move over the most challenging terrain. 

Key features for climbing backpacks: 

  • Moulded back panel that forms to your shape for comfort on the move. 

  • Tough and durable fabrics that stand up to sharp tools and rough rock. 

  • Multiple gear attachment loops such as daisy chains and ice axe holders. 

  • Adaptable for skiing or lightweight use with A-frame ski carry options or removable features. 

A runner wearing a Rab running vest in the mountains.
Running and fast hiking backpacks.
You need a close-fitting, body-hugging backpack or running vest that perfectly moulds to your shape and stays secure when you’re moving quickly. 

Key features for running and fast hiking backpacks: 

  • Ultra-lightweight construction and features with breathable back panel or vest-style design. 

  • Accessible stretch mesh pockets that can be used on the move. 

  • Vest-style or secure harness with double chest and waist strap for close-fit comfort. 

  • Easy-access walking pole attachments so you can keep moving. 

Four people ski touring across snow in the mountains.
Backcountry skiing backpacks.
You need a robust and secure backpack that will move with you on descents and ascents with compartments for key safety equipment in case of an avalanche. 

Key features for ski backpacks: 

  • Easy access pocket for shovel and probe. 

  • Tough, water-resistant construction to withstand sharp ski edges and all weathers. 

  • Ski carry options for boot-packing up steep ascents. 

  • Detachable helmet holder giving you extra volume inside. 

  • Snow-shedding moulded back panel for mobility on the move. 

Finally, make sure it fits.

It’s no use having the right hiking backpack if it doesn’t fit your body size. Some of our backpacks come in small, medium or large sizes, some come with adjustable back lengths, and we also make a huge selection of packs with Narrow Dimensions (ND). Our ND packs are built with different proportions to our regular packs, ideal for anyone with a smaller frame.  

Need help with backpack fitting? Check out our Backpack Size Guide.