How to Choose the Right Size Backpack for Hiking

Choosing the right backpack is crucial for any successful hike. You need to fit in all your essentials, but not be laden down with too much weight.

Go too large and you’ll either have loads of unused space, or be tempted to overfill - this can lead to an uncomfortable day’s hike. Too small and you won’t have everything you need to be safe, comfortable and hydrated.

When choosing a rucksack, the crucial question is how long you’ll be out and about in the great outdoors. Head out for an afternoon’s walking and you’ll only need a light bag, while three-day adventures will require a more substantial pack. If you’re an inexperienced hiker or you prefer more creature comforts, you may also need more space for your stuff.

Let’s take a look at the different sizes of rucksack, and what each is best used for.

As they are really lightweight, these smaller backpacks are best for fast-paced activities where you don’t want to be carrying too much. You’ll be able to fit in your water, snacks and an emergency layer or two, but not much more. These smaller rucksacks can also be used for short walks and hikes.

Planning a day or afternoon’s hike? Choose a 20-40 litre rucksack. You’ll have room to fit in all your essentials, including water, snacks, a map, extra layers and a couple of additional items. But crucially, these rucksacks are smartly designed and compact. This means they won’t weigh you down or hold you back.

If you’re heading out on a camping trip where you’ll be hiking for more than a day, choose a rucksack closer to 60 litres. This is a proper size for multi-day backpacking. Not only does it have a lot more capacity for clothes, food supplies and more, but it’s also designed to be more comfortable to carry with a heavy load. When adjusted to fit properly, these specially designed rucksacks distribute the weight evenly across your body. This means you can carry them for longer without discomfort. What’s more, they usually have extra straps and buckles for roll mats and sleeping bags, as well as lots of handy pockets.

If you’ll be away for up to a week or more, you’ll need to look at the larger end of the rucksack scale. An 85 litre backpack gives you all the capacity you need for a longer trip, while still being reasonably comfortable to carry. Remember to pack as light as you can though!

30 litre rucksacks are at the lighter and smaller end of the scale, measuring up to 53cm by 30cm. They tend to be quite compact and neat in design, fitting to the contours of your back. This makes them easier to carry than bulkier packs, so they’re perfect for shorter hikes.

As it's designed for longer backpacking adventures, a 65 litre pack can be reasonably bulky. Typically, these packs measure around 75cm in length and 35cm in width. You can also expect additional pockets, straps and buckles with this kind of rucksack, which can make it bulkier all round.

Choose a 65 litre rucksack if you’re camping overnight or will be away for a few days. It gives you plenty of space for everything you want to pack, but remember - it will get a little heavy. This makes it a poor option for shorter trips, as it could weigh you down unnecessarily.

If you’ve selected a 40 litre backpack for your trip, you can expect to fit in a decent amount more than the bare essentials. This is one of the largest daypacks around, perfect for full-day hikes where you need to be prepared for anything.

Inside a typical 40 litre rucksack, you should be able to fit:

• At least a couple of extra layers - for example, a light waterproof jacket and additional shirt or jumper
• An extra pair of socks
• A large water bottle
• A selection of snacks
• A hat and gloves
• Sun protection
• A map
• A phone and power bank for charging
• First aid supplies.

If you’ll be out for a whole day, it’s a good idea to go for a 40 litre backpack. This gives you plenty of room to pack extra layers in case the weather changes, as well as lots of food and drink. If you avoid packing anything too heavy, it should be a good size for carrying around all day too.