Choosing a bag
What size backpack do you need? A guide to litres and fit
Start with what you carry. Then check volume, shape and the space that pockets actually leave you.
In this guide
Litres help you compare backpack capacity, but they cannot tell you whether a lunch box will sit beside your laptop or whether a rigid folder will pass through the opening. Use volume to create a shortlist, then check dimensions and layout against your own belongings.
Start with your usual load
Lay out what you carry on a normal day: laptop or tablet, charger, notebook, bottle, lunch and an extra layer. Separate occasional items from daily essentials. A bag chosen around an exceptional once-a-year load can feel unnecessarily large for the rest of the year.
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| Capacity | A starting point for | Check carefully |
|---|---|---|
| Around 15 L | A compact daily load and smaller accessories. | Laptop sleeve dimensions and the room left after inserting it. |
| Around 20 L | Daily essentials with some room for lunch or a light layer. | Bag depth, bottle storage and the main opening. |
| Around 25 L | A bulkier daily load or light overnight packing. | Loaded weight and whether the bag feels too large for everyday use. |
Clothing size, packing style and the shape of your belongings change what fits. These ranges are planning guidance, not results from a packing test.
Compare real dimensions alongside litres
These examples use the current published DIYION specifications. Dimensions below are the outside height × width × depth, not laptop compartment measurements.
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| Model | Listed capacity | External dimensions |
|---|---|---|
| Yukon | 16 L | 42 × 31 × 12 cm |
| Göteborg | 18 L | 42 × 32 × 13 cm |
| Lund | 16–20 L | 43 × 31 × 12 cm |
| Coda | 22 L | 40 × 30 × 18 cm |
Do not multiply the outside dimensions to “correct” the listed litres. Padding, rounded corners, pockets and how the bag closes affect usable space.
Check the opening and the things that do not bend
A laptop, document folder or lunch container needs more than a volume figure. Compare each rigid item with the compartment and its opening. Roll-top bags also need enough fabric left to close correctly; filling the top to its maximum height can change how the closure works.
For a computer, follow our laptop backpack fit checklist. If you carry books, a book sleeve can keep their covers separate from loose items, but allow for the sleeve’s extra thickness.
Check the size on your body
Compare the stated height and width with a backpack you already own. If yours feels comfortable, those measurements provide a more useful reference than a model photograph alone. Look at strap adjustment and how far the bag projects from your back when filled.
Pack heavy items close to the back panel and avoid letting small dense objects collect at the bottom. Adjust both straps before judging comfort. A larger bag with spare room does not need to be filled.
Choose for the trip you actually make
For a daily bag, begin with canvas backpacks or leather backpacks. For two nights away with a change of shoes, compare a weekend bag and use our two-night packing checklist.
If you plan to fly, compare the packed external dimensions, including protruding pockets and handles, with your airline and fare’s current allowance. Litres alone never establish cabin or under-seat acceptance.
Questions answered
Is 20 L enough for a laptop?
Possibly, but volume does not establish laptop fit. Check the actual laptop compartment dimensions, the opening and the space needed for your charger and other belongings.
Is a bigger backpack always more comfortable?
No. Fit, straps, empty weight and how you pack it matter. Compare the loaded bag with your normal daily needs.
Explore the models
See the current colours, specifications and product photographs.
Keep exploring
How to choose a laptop backpack that actually fits
Screen inches are only the start. Three measurements and a quick compartment check make a better shortlist.
Read the guide
Roll-top or zip backpack: choose the opening that suits your day
Fast access or a flexible top? Compare the details you will notice every time you open your bag.
Read the guide
How to choose a bag as a gift without guessing the fit
Start with the way they spend their day, then narrow down the shape, material and details.
Read the guideDIYION / Canvas backpacks
Put the advice into practice
Compare the details, colours and dimensions in the collection.
Canvas backpacks
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