So you’re in the market for a backpack. (Yeah! Adventure time!)
But now you need an answer to “What size backpack should I get?”
The amount of stuff a bag will hold is indicated by either a liter or cubic inch number. But what do those numbers mean? How big is a 40 L backpack, exactly? How many cubic inches do I need in a backpack?
This is a visual thing, so I made you a quick video to explain.
Watch how much stuff you can fit in bags between 15 and 70 L. (That’s 900 to 4300 cubic inches.).
Did you catch that the 40L bag fit more than the 46L bag? How could that be?!
There’s no backpack volume measurement authority to say how measuring has to be done. Company A might use bags of rice. Company B might use ping pong balls. Your practical budget travel blogger uses t-shirts! So while you’re reading backpack reviews, you’ll see things like someone fitting as much in an Osprey Porter 30 as a Farpoint 40.
How to Size a Backpack
Now you know the volume of bag you want, but you might also need to figure out the size. Many travelpack backpacks are one-size-fits-all. But other bags have sizing – generally SM- MED – LG – that correlate with your torso length.
Your torso is your body, minus your head and limbs. Measure from the bump at the base of your neck to your hip bones. Each bag size accommodates torsos within a small range.
Common torso ranges are:
XS: 0-39cm (0-15in)
S: 40-45cm (16-17.5in)
M: 46-50cm (18-19.5in)
L: 51cm+ (20in+)
How to Pick a Good Travel Backpack
There are four things everyone needs to think about then choosing a travelpack backpack. Physical comfort, ease of use, what the backpack is like in transit, and how secure it is.
Everyone has different preferences and requirements in each of those areas. I’ve written an entire article with all the backpack features explained. Read: How to Pick a Good Travel Backpack
Which Backpack is Best for Traveling?
If you’re willing to listen to my opinion gained from years of traveling experience – including my current streak of nearly 9 years straight – I’ll let you in on a little secret. There is no holy grail.
For my opinion on which bags are good for which reasons, check out my reviews of 25-55L backpacks.
What Should I Pack?
I’m the author of the most thorough international travel packing list that exists. I explain what to bring and why. I explain what not to bring and why. I pass on the advice from hundreds of travelers who have written in to share their experiences.
Check it out!