The Ultimate Guide to Backpack Sizes & Volumes

Backpacks are great because they easily hold all sorts of things you'll need for an adventure. Before you rush out to buy one, it's best to understand the standard backpack sizes and volumes. In this ultimate guide, we've detailed the sizes and uses for each so that you can make the ideal purchase.

Why Does Volume Matter?

A backpack's volume tells you how much it can hold based on size. Manufacturers convert this into liters because that's the unit we use when discussing how much space something takes up.

So why use liters, a unit type for liquids? Because a liquid is free-flowing, it spreads to use as much space as possible. Although you're not filling your bag with water, you will pack it with various physical objects. Knowing how much you can put into it makes that process easier.

Volume and Dimensions

We use dimensions to measure items ranging from furniture to luggage. It's important to note that volume doesn't replace dimensions. However, measurements can impact volume since higher dimensions mean more space in the bag. Therefore, when shopping for a backpack, you should evaluate the dimensions and volume to find your perfect option.

Common Backpack Sizes

Backpacks come in various sizes, and each option best serves a different purpose. The most common backpack sizes are:

• Nine Liters
• 25 Liters
• 35 Liters
• 45 Liters
• 50+ Liters

Anything nine liters or under is more of a mini backpack. Some use these instead of a purse on vacations. On the other hand, your standard school bag is around 25 liters. While additional sizes are available, we’ve listed these options because each hits the mark between those ranges.

Nine-Liter Backpacks

This size is ideal if you need something to carry a few small belongings for a day out. So, if you go hiking for a few hours, you'll need water and a snack. Since the packing list usually ends there, a nine-liter bag will easily carry everything. Plus, since it's small, you won't have to worry about it weighing you down as you explore nature.

Many refer to a nine-liter backpack as a mini backpack because of its small size. Aside from hiking, you could also use it for going into the office or for a few hours at the gym.

25-Liter Backpacks

This is the size most of us are familiar with, and it's ideal for any athlete planning a day of physical activity. A 25-liter backpack is also suitable for anyone planning a day trip where you don't need an excessive number of items.

If you go on a day-long hiking trip, you'll need water, a mid-day meal, snacks, and first aid materials. You may also have some gear or a change of clothes. Trying to squeeze all that into a nine-liter bag isn't possible. Anything above 30 liters may be too big. As a result, the 25-liter backpack is your perfect option.

Some people also use 25-liter bags to carry their laptops and other work essentials, plus gym gear to exercise after work. Others use a 25-liter bag for school because it's large enough to hold all their supplies.

35-Liter Backpacks

Your 35-liter backpack is ideal for a multi-day trip. If you plan to go on a long hike and camp along the way, you'll easily fit everything needed into this bag. This option is also the perfect piece of luggage if you plan to go on a weekend vacation. Typically, any backpack 35 liters or more is a multi-day bag.

With this size bag, you can easily pack like a minimalist and ensure you don't waste space on items you don't need. This is especially helpful when traveling by plane since most of us avoid checking baggage whenever we can. You can tuck a 35L bag under most airline seats, so you won't have to worry about space in the overhead bins.

45-Liter Backpacks

Up next in our guide to backpack sizes and volumes is the 45L. If you plan to go on an adventure beyond two days, then a 45-liter bag will give you the needed space for packing. You'll easily fit:

• Camping gear
• Multiple changes of clothes
• Food
• Water

Many backpackers use a bag of around 45L because it's easier to carry than a suitcase. You'll also be able to fit a light sleeping bag or mat and some cooking gear into this size option to ensure the perfect adventure. With everything in a single pack, you can enjoy the great outdoors while knowing everything you need is on your back.

Buying a 45L Backpack

WOLFpak sells 45L tactical backpacks that are durable and perfect for any adventure you've planned. With all the pockets in our knapsacks, you'll also easily organize all your belongings. So, invest in a bag that'll easily hold the many things you need.

50-Liter Backpacks and Beyond

Anything above 50 liters is on the extra-large end, and most use these for extended travel or journeys where they need a lot of gear. For example, if you plan a week-long hiking trip across various terrains, you'll need something 50 liters or larger.

Tips for Buying a Backpack

Purchasing the ideal backpack depends on what you need it for. Do you need something to hold your workout clothes and other gym essentials? Or are you looking for a bag to take on an overnight hike? You don't want to buy the wrong size because it won't assist you as much and may even hinder your travels. Also, look for padded straps and a hip belt to prevent the risk of back pain when you need to carry a heavy load.

Prioritize Durability

Material is another crucial part of purchasing the best backpack. The bag should be durable and made with a fabric strong enough to hold everything. You shouldn't start noticing tearing along the bottom, sides, or straps after only a few uses.

Shop at WOLFpak

At WOLFpak, you'll find high-quality backpacks in 9L, 25L, 35L, and 45L. We've carefully designed our bags to give athletes the space they need for a day at the gym or a multi-day journey. Invest in a bag that'll carry all the things you need.