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Cars & travel.

Updated: 29 Jun 2021

Backpack buying guide

From gap year travels to your daily commute, backpacks are specially designed for a range of activities.
Which?Editorial team
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Storage capacity and features to look for will depend on what you're going to be using your backpack for, but there are some important things to consider to make sure you buy the right backpack for your needs.

Adjustable or fixed frames

The right fit is crucial when it comes to backpacks, but as everyone is different, you really do need to try them on before you buy. Backpacks can be divided into two when it comes to frames:

  • adjustable frames
  • fixed frames

Adjustable frames allow you to lengthen or shorten the back. They tend to be heavier, but the upside is you can adjust them to your torso length until you get the perfect fit. And you can share one pack between two people simply by adjusting the frame depending on who’s turn it is to do the carrying.

If you’re buying a fixed-frame model it’s even more essential that you try the pack on, load it with a few heavy items and walk about to see how it feels. Good retailers will be happy for you to do this in the shop. If you’re buying online, don’t remove the tags or throw away the packaging until you’re sure it’s right.

Women may find they get a better fit from a women’s backpack that’s designed to fit the female hip-to-torso ratio more effectively.

See our reviews of the best headtorches and family tents

Hip belts for support

Despite the fact that they’re called backpacks, the bulk of the load should be supported by your hips, not your back. A well-fitting hip belt (that sits on the hips, not round your waist) is the key to minimising the strain on your spine and shoulder muscles.

Some Osprey backpacks can have the hip support heat moulded for the perfect fit, and this proved popular with Which? members who tried it. This is only available at a few specialist retailers, though.

Backpack storage capacity

The size of backpack you need depends on what you intend to use it for – too big and you’ll end up carrying more weight than you need, too small and you’ll struggle to fit everything in.

Backpack capacity is measured in litres, and typically varies from 20-80 litres. It’s hard to visualise ‘litres of space’, but as a general guide:

  • 20 litres: sometimes called daypacks. Suitable for day trips where you’ll only be carrying lightweight waterproofs, some lunch and a couple of drinks.
  • 30-50 litres: Suitable for a winter day trip or a weekend away.
  • 70-80 litres: More suitable for longer camping trips or expeditions.

Other backpack features to look out for


A padded hip belt and shoulder straps can go a long way to reducing discomfort on a long hike with a heavy pack. Even in summer with a lightweight pack, check that the strapping fabric isn’t too rough, as you may be able to feel it rubbing through lightweight clothing.


If you tend to build up a sweat, look for a backpack with a specially designed ventilation mesh or shaping that allows air to circulate between your back and the pack. Several of you mentioned good ventilation as a plus point in our customer survey of backpack likes and dislikes.


It can be annoying enough if you get caught out in a downpour without the added hassle of all your gear getting soaked. Some backpacks are made of waterproof fabric, which can help to keep the worst of the weather off - but to make extra sure you might want to look for one with an integral rain cover.

Pockets and clips

Easy-to-reach mesh pockets for water bottles, secure pockets for your phone, and clips or straps for fixing items, such as walking poles, to your pack were all popular in our member survey.