How Big is a 40 Liter Backpack? Key Insights into 40L Backpack

When hiking, exploring new things in nature, or on professional trips, you always need a backpack that can accommodate all your accessories. A bag pack ensures that you have an ideal space to keep your essential things and provides a perfect weight balance. It’s always tricky to decide which bag size suits you as bag packs come in sizes such as 20L,30L, or 40L. If you want to know how big is 20L backpack. Check out our guide!

However, people choose 30L or 40L size backpacks. Focusing on 40L backpack, a 40L backpack is a popular choice for travelers who want to balance size and capacity. But how big is it, and what factors should you consider before buying a backpack?

In this article, you will find detailed information on a 40L Backpack. Read the post to discover why a 40 L backpack is a good choice.

Is a 40L Pack So Large?

Is a 40 liter pack so large

It is big enough for traveling. Consider it a relatively large bag. It allows you to pack more oversized items, such as a tent or sleeping bag. In terms of packing, it offers excellent versatility and flexibility, but again it depends on your packing style. If you are a packer, you may need a different size. Let’s get into more details about a 40L backpack.

How Many Days Can You Comfortably Carry in a 40L Backpack?

The question that needs a satisfying answer is this: you are wondering if you have a 40L backpack and if you have a 3 to 4 days trip, what to carry in it comfortably.

So it depends on three things.

  1. Your preferences
  2. Your packing skills
  3. The number of days you have planned.

Here are some tips to help analyze how many days you can comfortably carry in a 40L backpack.

  • You can carry camping gear, a sleeping bag, and clothes for a weekend trip.
  • For a three to four days trip, add a small tent, essential cooking equipment if you can carry it, a sleeping bag, and a pack of clothes if you are comfortable with re-wearing.
  • If you planned an entire week trip, pack more efficiently and go for dehydrated food items.
  • For longer trips, you have to consider a bag bigger than 40L.

How Much Weight Can You Comfortably Carry in a 40L Backpack?

How much weight can you carry in a 40L Backpack

The key point you should keep in your mind is to listen to your body. If you are going hiking with this bag, then pack accordingly. How much you can carry in a 40 L backpack depends on several factors, such as

  • Terrain (Area you are visiting)
  • Altitude
  • Temperature
  • The individual’s fitness level

These factors mentioned above will define your comfort.

Coming towards the point, how much weight you can carry depends on how much your weight is. A person can hold 20 to 25 % weight of their body weight. It sounds challenging to understand! Here’s an example for you. If you have a body weight of 150 pounds or 68 kg, your backpack should weigh 30 to 37.5 pounds or 15 to 18 kg.

 However, a typical empty 40L backpack weighs approximately 2 to 4 pounds (0.9 to 1.8 kg). What items you will pack in it determines the actual weight. So pack according to your body weight and health. If you travel by air, keep the airline’s guidelines on how much weight or the bag pack size they allow.

Shortly try to pack the necessary things and ensure the balance between your body weight and your backpack weight to avoid any injury or discomfort if you are going for a hike.

40 Liter Backpack Size and Dimensions

If you want to understand the size of a 40L backpack, it’s essential to know how it’s measured. Typically, backpack manufacturers measure the volume of all compartments, including the main compartments and any open and closed pockets. The measurements are then converted from cubic inches to liters and rounded to the nearest decimal point. So, a 40L backpack measures approximately 2,440.95 cubic inches.

 Dimensions of the Backpack may vary based on brand and model. 20.5 x 13 x 7.1 inches is the average dimension of a backpack whose capacity is 40 liters.

How to Measure Your Backpack Dimensions?

How to measure your backpack dimension

Following these steps, you can measure the dimensions using a tape or ruler. These measurements will help you to choose a suitable bag for your travel.

  1. Put your backpack on a flat surface.
  2. Select the length, width, and height as the three dimensions of the backpack to measure.
  3. To measure length, start at the bottom of the backpack and measure up to the top. Attempt to measure the lengthiest part.
  4. Place the tape measure or ruler at the backpack’s widest point, then measure across to the opposite side to determine its width.
  5. The height of the backpack should be measured by starting with the ruler or tape measure at the bottom and moving up to the highest point.
  6. You can measure the specific measurements of each compartment if your backpack has many.
  7. Write down the measurements in inches or centimeters.

Maximize Space: Expert Tips for Packing Your 40L Backpack Efficiently

A 40L backpack is a good choice when you are not an over-packer. By over-packer, I mean it depends on your packing style. If you are a person who adds too many items in a packing bag, it means a 40 L will also not be going to help you. Here we will provide you with some tips on how to pack your 40L backpack efficiently; let’s get into them:

  • Be Realistic and Practical: When packing for a trip, try the realistic and practical approach, do not add unnecessary things. For example, if you can re-wear your cloth, add fewer clothes.
  • Make A Packing List: If you have a packing list, it will ensure you pack the bag appropriately. Later in this article, you will find a list of things you can add.
  •  Compression Sacks: When you use compression sacks for heavy items such as sleeping bags or tents, etc., it reduces the volume by compressing the bulky items.
  • Pack Strategically: you should put the less useable items at the bottom and frequently used items on top, saving you time when needed. Also, pack in layers and roll your clothes to use space more efficiently.
  • Utilize The Outside Straps of Your Backpack: a backpack contains many straps and loops outside. You can attach some items on these straps, e.g., Tents, and sleeping pads, to free up inner space.

Things to Consider for 40-liter Backpack Size

If you are traveling by air, carry your packing items according to the carry-on luggage guidelines of the airline. Here’s a packing list for a 40L backpack,

  • A laptop up to 15 inches in size
  • 2-3 extra sets of clothing
  • One additional pair of shoes
  • A warm jacket
  • A travel pillow
  • Toiletries and makeup
  • Headphones
  • A power bank
  • Cords and cables
  • A tablet
  • Some snacks
  • Portable charger
  • An A4 notebook
  • One or two magazines
  • Maps
  • Keys
  • Passport
  • Wallet
  • Sunglasses
  • Pens
  • A book
  • An umbrella
  • A water bottle.

Add or subtract these accessories from your packing list according to your needs and travel.

Expert Tips and Advice

  • Choose a backpack with adjustable straps and hip belts.
  • Consider the weight and distribution of your gear to prevent discomfort and injury.
  • Pack the heaviest items in the compartment that is close to your back.
  • If it’s a one-day trip, Wear the items such as a camera instead of packing it to reduce the weight on the backpack straps.
  • One tip that can help you reduce weight is choosing lightweight gear, such as a lightweight sleeping bag and tent.
  • Ensure the weight is evenly distributed to your backpack’s right and left sides.
  • Organize your items in compartments and pockets to improve accessibility and convenience. Pack snacks and food items in your outer bags to take them out quickly.
  • You can use a water bottle with a hydration tube, so whenever you feel thirsty, by having that tube, you can quickly drink water without lifting the backpack down.
  • Invest in a waterproof cover or pack liner to protect your gear from rain and moisture.
  • Last and essential tip, do not pack your backpack full. Leave some space in it. Use that space to place extra food items you may buy during travel.


A 40L backpack is the best to choose from if you need a larger bag for your travel. It depends on your preferences and packing skills, and you can easily fit the more oversized items. The typical empty weight of a 40L backpack is between 2-4 pounds, but the actual weight will depend on the things you pack. The dimensions of a 40L backpack can vary, but on average, they are around 20.5 x 13 x 7.1 inches. Pack your gear efficiently, pack only necessary items and compression bags, and distribute the weight evenly to avoid discomfort or injury.

When you are done with your adventure, store your backpack correctly to maintain backpack’s shape and prevent any damage!


How many kgs can a 40L backpack hold?

A 40L backpack, when empty, weighs up to approximately 0.9 to 1 kg (2-4 pounds), but when you fully pack it up, most of the time it weighs between 11 to 13 kg. in other words, a 40L backpack can hold more than 10kg weight.

Is a 40 L backpack enough for a three weeks trip?

If you need a much larger bag for a three weeks trip, here’s an answer: you can choose a 40L backpack. If you pack smartly and efficiently, this size is enough for you.

What is the difference between a 30L backpack and a 40L backpack?

The significant difference between these two is the size of the main compartment and the number of dividers. A 40L backpack contains more walls and a larger main room making it suitable for longer trips.

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