Backpack Sizes in Liters – How to Choose The Right Size

There are plenty of backpack options in the market, ranging from sizes, fabric, adjustability features, and much more. Because of the plethora of options, choosing the right backpack can be a really tricky task. However, before even plunging into questions of features and fabrics, a decision has to be made about the backpack size itself. Whether it is that trekking trip you have been planning to go on, or a sudden business trip that requires you to be out of town for a while, choosing the right backpack size is the first decision to be made.

Backpack sizes are usually made available in liters. However, it can be challenging to translate what a volume capacity in liters actually means in terms of the objects that can be contained. This guide is written to help you make sense of how volume capacity translates into how much stuff you can carry. Not only is it the amount of weight that one is willing to carry that determines the backpack size but a range of other factors as well. These factors include length of trip, luggage weight, weather conditions, and activities on the trip. These factors can serve as a guide in determining which backpack size to opt for.

This article is divided into two parts mainly. Firstly, we look at the many factors to keep in mind when deciding the right backpack size. Secondly, we look at the different options for backpack sizes in liters and how much they can contain.

Factors to consider

1. Length of the trip

How long your trip is the most important deciding factor for choosing the right volume capacity of the backpack. For day long trips, 35 liter backpacks work best while for week long or even longer trips, a backpack with more than 70 liter capacity would work. Similarly, for a three to five day long trip, a volume capacity range of 50-80 liters work while weekend trips can work with under 50 liter backpacks.

2. Luggage Weight

While the duration of one’s trip is a primary factor in deciding your backpack size choice, the amount of luggage weight one carries is quite significant as well. For instance, while a 35 liter backpack is recommended for a one day long trip, a light packer can probably work with a backpack of lesser volume. Essentially, this factor largely depends on the kind of packer you are. While light packers are both disciplined and well-organized when it comes to packing, for someone inexperience, this might be too much of a hassle and could compromise on your trip comfort.

3. Weather Conditions

While weather conditions also influence other factors such as the fabric and presence of rain cover in a backpack, they are also important in choosing the size of your backpack. For winters, one generally requires a larger backpack for heavier clothing while for summers, a backpack with lesser capacity can also make do. Similarly, a rainy weather may require you to carry some additional clothing or equipment. As such, watch out for the weather conditions and the additional luggage that might require you to carry.

4. Activities on the trip

Activities such as picnic or camping can create room for further belongings to be contained in one’s backpack. As such, this is an essential factor to determine how much volume one actually requires. Similarly, any additional specific clothing you need to carry for certain events or festivities on your travel may require more room.

5. Backpack fit

While we are about choosing the right backpack size, a factor that is extremely important is the backpack fit. This consists of two things essentially: the size of the hip belt and the length of the suspension system. The size of the hip belt is critical determining if you will be able to carry the load efficiently or not. For you to carry the weight effectively, most of the weight has to rest on the hips so that they can distribute the weight to larger bones and muscles. Nearly all backpacks have an adjustable hip belt that can help you fit the hip belt correctly, but some even offer interchangeable belts to reach the most optimum fit.

The shoulder harness system, similarly, is also a critical part of the backpack fit. Backpacks are sized according to the length of one’s torso rather than height. Moreover, there different manufacturers do not follow the same sizing standard and as such, it is essential to measure oneself. The measurement that matters here is from the prominent bone at the bottom of your neck (known as the C7 vertebrae) down to the top of your hip bone (known as the iliac crest). Usually, this measurement is in the 16 to 23 inch range. Based on this measurement, you can check out a specific backpack sizing chart and choose the right fit for you.

More so, women-specific backpacks have narrower and shorter torso options, and these can be availed by men who find themselves in such a situation.

Common Backpack Sizes

Day or Overnight Trips

For day trips or an overnight we recommend around a 30 liters backpack size.

For overnight trips, 30 liter backpacks are also ideal whether it is for hiking purposes or travel. When it comes to hiking, an even shorter backpack can work if you are a light packer. However, a 30 liter one provides ample room for a picnic lunch, snacks, tech equipment like camera gear. More so you can toss in an emergency raincoat for unforeseen weather conditions. As such, the 30 liter backpack provides a spacious option for day long trips.

When it comes to travel, a backpack is just a lot more convenient than a standard roller luggage. It provides you a lot more flexibility and mobility. Most backpacks come with essential adjustability options that fit your body shape and size without hurting your back or placing uneven weights. Similarly, most backpacks are cautious of airline luggage limits and are designed to comply with these limits. Regardless, it is always best to check the airline’s maximum carry on luggage limit.

Our picks for the Best Backpacks for Day Trip

Lastly, when it comes to travel, a small, zipped backpack is essential. By simply purchasing a 30 liter backpack, you need not carry any additional backpacks with you either. More so, these zipped backpacks are secure, and some come with additional layers of security such as a mesh layer atop the zipper and so on.

Weekend trips (1-3 nights)

Recommended backpack capacity: 30-50 liters

For weekend trips that can go up to three nights, backpacks in the 35-50 liter range are ideal whether it is an overnight hike or a travel plan. They also work well for lightweight hikers.

When it comes to hiking, an overnight hike or a weekend adventure, one requires a backpack that is spacious enough to contain necessities such as enough clothes, food and water, sleeping gear, and a tent.

For light packers who want to make such a backpack work for a multi-day hike plan, certain additional factors may be needed to make it more convenient. For instance, a lightweight tent, lightweight sleeping mats, as well as a packable, lightweight cooking gear. However, not everyone is a disciplined light packer and may need a backpack with more volume.

A bigger backpack has its own advantages too. For instance, one does not have to compromise on the need for comfort, warmth, and safety. One can simply pack in some extra clothes, extra food, etc. This again depends on a number of factors such as the climate where you are travelling, and so on. Similarly, a longer trip would simply require you to dedicate an important volume of your backpack to food and water, especially so if you are hiking for more than a few days. Not only do you require adequate supplies of food and water daily but also an extra day’s worth of food and water in case of an emergency situation.

Our picks for the Best Backpack 50L

While a 40 liter backpack is spacious enough to contain a small tent, a backpacking sleeping bag, extra clothing and extra layers. More so, this can still fill in other essentials such as a small stove along with basic utensils for cooking, a water filter/purifier, navigation tools, and a first aid kind. Furthermore, depending on how well-packed one’s backpack is, some additional items can be added as well such as a coffee press, a lightweight chair, or a small camp lantern.

Multi-day trips (3-5 nights)

Recommended backpack capacity: 50-80 liters

Whether it is a longer multi day hike or a long travel plan, backpacks with capacities larger than 50 liters provide ample space. A multi day hike journey would require one to carry kit such as shelter, sleeping gear, clothing for different conditions as well as enough food. For such needs, a backpack with a size over 50 liters is the best backpack for one.

While packers may consider decreasing their load by removing belongings, removing certain equipment could place one at a disadvantage. For instance, removing contents from one’s sleeping gear is probably not a good idea as hiking trips are quite exhausting and a good night’s sleep is one of the essentials. At the very least, it is essential to keep a warm sleeping bag, a sleeping mattress, some garments that can be used as a makeshift pillow.

In order to cut out on belonging, unnecessary clothing can be replaced by packable, lightweight gear. Moreover, an appropriately sized and compartmentalized backpack can better accommodate the hiking essentials in a way that keeps them organized and packed well.

When it comes to travelling, a backpack with a capacity greater than 50 liters can work really well for someone looking to backpack around countries for a few months. This is because these bags are quite spacious and permit a number of clothing options. Similarly, these backpacks are quite ideal for plans that are a combination of travelling and hiking.

Extended trips (longer than 5 nights)

Recommended volume capacity for backpacks: 80 liters or more

For trips that are longer than five days, especially hiking trips, a backpack with volume capacity greater than 80 liters is essential. Similarly, this particular backpack option is also more suitable for winter travel plans when one has to carry heavier clothing. More so, these backpacks offer a greater diversity of options such as the space to accommodate extra clothes, a warmer sleeping bag, a four-season tent. Furthermore, these backpacks are also a great option for parents travelling with children as parents have to carry their luggage as well.


In conclusion, the right backpack size really depends on one’s specific needs and conditions, the nature and duration of travel, the climate of the location, the number of people one is travelling with and so on. In order to decide which backpack to choose from the various backpack sizes in liters, make sure to carefully weigh out the different factors for your particular situation.

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