How do I choose and fit a rucksack?

We get asked a lot of questions about buying a rucksack. Here are a few things to consider.

What size rucksack do I need?

This will depend on what you are intending to do with it. For example, will you need to carry equipment for camping or for a multi-day trek? Or are you planning to use it for day hikes only?

What am I going to use it for?

Will you do any mountaineering and therefore need specialised features such as ice axe loops or helmet mesh?

What features will I need?

For example, attachment loops for trekking poles. Do you prefer a camelbak or a platypus water bladder? You’ll need a sack which can take that system. Or do you prefer to carry water in bottles? In which case you’ll need a sack that has outside pockets or attachment points to carry and reach them.

What size am I?

And does this place any constraints on the size of my sack? For instance, small or slender women may need a daypack with a small back frame, a smaller hip belt and narrower shoulder strap settings.

Always make sure your rucksack is the correct length for your back. When you have it comfortably positioned on your hips (see fitting guidelines below) the back length should not be longer than the top of your shoulders, or at most the nape of your neck. If you have a top pocket, fill it with something and then tilt your head back – does the rucksack rub on your head or get in the way of your head movement? If so, the rucksack is too long.

As a general guideline for our trekking trips in Europe, we recommend a rucksack between 20 and 30L capacity. It is perfectly possible to use larger rucksack with compression straps if you want to buy a multipurpose one or use an existing one; however, it must be a good fit to your body and the compression system must work effectively so the load isn’t all at the bottom. We would not recommend going below 20L minimum, as you must have enough room to carry plenty of water as well as (possibly) waterproofs and warm layers, and of course your picnic lunch.

It is never a good idea to use a sack which is too small to the point that
you have to hang random belongings on the outside of the rucksack.

Choosing the right rucksack for you is half the battle; fitting it correctly is the other half, and here we find that people are often wearing their sacks incorrectly fitted. Many outdoor shops do not offer really good advice on rucksack fitting, and it is crucial to being able to wear it comfortably even when carrying a heavy load.

How to correctly fit your rucksack

The golden rule with fitting your rucksack to your body is to always work from the bottom up. You will need a half- or full-length mirror, and possibly a friend to help you with step 3 below.

Step 1
Put some weight and bulk into it. You don’t need to go mad with bricks or anything, but you can’t fit an empty rucksack. Ideally, approximate the weight and bulk you’d carry for a day hike.

Step 2
Loosen off the main shoulder straps (the ones that your arms go through) and the top shoulder straps if your daypack has them (the ones that go from the top of the daypack to join your main shoulder straps some centimetres along). If you’re using a larger rucksack, also tighten the compression straps to slim it down. In this case, aim for a taller skinnier rucksack not a shorter dumpy one.

Step 3
Now put on the rucksack and do up the waist/hip belt tight (you might find a friend to help users, as your rucksack has some weight in it and the shoulder straps are loose). The belt should be tight enough that if you wiggle your shoulders around you can feel the rucksack sits on your hips and doesn’t move. You shouldn’t be able to slide more than your thumbs between the belt and your body.

Step 4
There is no one perfect positioning point for the waist/hip belt, it depends on your body shape and personal preference. As a general guide, aim to have the weight sitting on top of your hips. Experiment if necessary to find what feels right to you. This waist/hip belt is the essential foundation on which the whole fitting of your rucksack rests – always do it first and make sure you have it correct. The mirror is helpful here.

Step 5
Once the waist/hip belt is in the correct position and tight enough, do up the main shoulder straps. Do not have these straps too tight! There should be a little bit of movement and air between the rucksack and your body. Also, look at yourself face-on in the mirror and check that the shoulder straps are a good fit – they should not be too wide apart (this is sometimes a problem with smaller people).

Step 6
Now do up the chest strap, if you have one. This definitely does not need to be tight! It is absolutely not load-bearing; its function just is to stop the shoulder straps either slipping off or rubbing on your armpit area. If you have to have the chest strap done up really tight to prevent this, you probably have the wrong size daypack.

Step 7
Finally, do up the top shoulder straps but again do NOT overtighten these! Their main purpose is to bring the rucksack closer to your body for extra balance if you are either carrying a very heavy load or scrambling over very rough bouldery terrain. If you have them too tight all the time you will make your shoulders sore and achy as you will be transferring too much weight to the upper body (this is also true of the main shoulder straps to some extent).

Step 8
Look at yourself in the mirror – you should be able to see that most of the weight is on the hips and that there is a bit of room between the top shoulder straps and the rucksack. The back length should be right for you.

Step 9
Now walk around a bit, walk up and down some stairs, bend over and pick something up off the floor; test how it feels while moving. Take the time to really check out the fit before you buy it.

Now that you have a correctly-fitted daypack (whether it’s a brand new one or an old friend), there is one last thing to consider: waterproofing your belongings.

‘Waterproof’ rucksack covers

Many daypacks come with integral waterproof covers. This is absolutely fine; they can certainly help keep showers or light rain at bay, and they can definitely come in handy. However, no daypack cover will ever be able to keep your belongings dry in a real downpour, or a consistent day’s rain. They can’t achieve this because they don’t cover the part that is against your body. So, by all means, use your rucksack cover, but don’t rely on it to keep everything 100% dry in heavy or constant rain, because they can’t do this. Our recommendation is to also use an internal lightweight drybag (or several drybags); you can find these in all different sizes and colours, and they are worth their weight in gold. We strongly recommend getting at least one of these; they are a really good investment. You can also use bin liners but they do tear easily and don’t last.

If your rucksack doesn’t have an integral waterproof cover, be very careful if you are planning to buy a separate one. Make sure it fits your daypack well. Covers that are too big can act as giant sails on windy mountaintops! They also tend to ‘pool’ rainwater in the excess fabric at the bottom of the rucksack, so you end up carrying a mini-lake round with you, into which you will firmly plonk your rucksack when you set it down.

If you don’t already have a daypack cover, in all honesty, the best use of your
money to solve the waterproofing issue will be to buy a good drybag.

Avoid a rucksack made out of ‘waterproof’ fabric because these are very heavy. They also keep water in as well as out, so if you pack so much as a wet pair of socks, you’ll find the rest of your sack is damp and musty. Also, avoid the temptation to use a poncho-type waterproof jacket and therefore assume that your rucksack will be covered by this. On mountains, in high winds, ponchos act like giant sails – like overlarge rucksack covers, only worse. They move about all over the place, your rucksack will inevitably get wet, and you might get blown off the mountain. Ponchos are fine as a back-up plan in good weather in benign territory but are not suitable for serious mountain weather conditions.