My 40-liter backpack travel guide

2022 Jun 20 See all posts

My 40-liter backpack travel guide

Special thanks to Liam Horne for feedback and review. I received no money from and have never even met any of the companies making the stuff I'm shilling here (with the sole exception of Unisocks); this is all just an honest listing of what works for me today.

I have lived as a nomad for the last nine years, taking 360 flights travelling over 1.5 million kilometers (assuming flight paths are straight, ignoring layovers) during that time. During this time, I've considerably optimized the luggage I carry along with me: from a 60-liter shoulder bag with a separate laptop bag, to a 60-liter shoulder bag that can contain the laptop bag, and now to a 40-liter packpage that can contain the laptop bag along with all the supplies I need to live my life.

The purpose of this post will be to go through the contents, as well as some of the tips that I've learned for how you too can optimize your travel life and never have to wait at a luggage counter again. There is no obligation to follow this guide in its entirety; if you have important needs that differ from mine, you can still get a lot of the benefits by going a hybrid route, and I will talk about these options too.

This guide is focused on my own experiences; plenty of other people have made their own guides and you should look at them too. /r/onebag is an excellent subreddit for this.

The backpack, with the various sub-bags laid out separately. Yes, this all fits in the backpack, and without that much effort to pack and unpack.

As a point of high-level organization, notice the bag-inside-a-bag structure. I have a T-shirt bag, an underwear bag, a sock bag, a toiletries bag, a dirty-laundry bag, a medicine bag, a laptop bag, and various small bags inside the inner compartment of my backpack, which all fit into a 40-liter Hynes Eagle backpack. This structure makes it easy to keep things organized.

It's like frugality, but for cm3 instead of dollars

The general principle that you are trying to follow is that you're trying to stay within a "budget" while still making sure you have everything that you need - much like normal financial planning of the type that almost everyone, with the important exception of crypto participants during bull runs, is used to dealing with. A key difference here is that instead of optimizing for dollars, you're optimizing for cubic centimeters. Of course, none of the things that I recommend here are going to be particularly hard on your dollars either, but minimizing cm3 is the primary objective.

What do I mean by this? Well, I mean getting items like this:

Electric shaver. About 5cm long and 2.5cm wide at the top. No charger or handle is required: it's USBC pluggable, your phone is the charger and handle. Buy on Amazon here (told you it's not hard on your dollars!)

And this:

Charger for mobile phone and laptop (can charge both at the same time)! About 5x5x2.5 cm. Buy here.

And there's more. Electric toothbrushes are normally known for being wide and bulky. But they don't have to be! Here is an electric toothbrush that is rechargeable, USBC-friendly (so no extra charging equipment required), only slightly wider than a regular toothbrush, and costs about $30, plus a couple dollars every few months for replacement brush heads. For connecting to various different continents' plugs, you can either use any regular reasonably small universal adapter, or get the Zendure Passport III which combines a universal adapter with a charger, so you can plug in USBC cables to charge your laptop and multiple other devices directly (!!).

As you might have noticed, a key ingredient in making this work is to be a USBC maximalist. You should strive to ensure that every single thing you buy is USBC-friendly. Your laptop, your phone, your toothbrush, everything. This ensures that you don't need to carry any extra equipment beyond one charger and 1-2 charging cables. In the last ~3 years, it has become much easier to live the USBC maximalist life; enjoy it!

Be a Uniqlo maximalist

For clothing, you have to navigate a tough tradeoff between price, cm3 and the clothing looking reasonably good. Fortunately, many of the more modern brands do a great job of fulfilling all three at the same time! My current strategy is to be a Uniqlo maximalist: altogether, about 70% of the clothing items in my bag are from Uniqlo.

This includes:

There are other stores that can give you often equally good products, but Uniqlo is easily accessible in many (though not all) of the regions I visit and does a good job, so I usually just start and stop there.


Socks are a complicated balancing act between multiple desired traits:

The ideal scenario is if you find low-cut or ankle socks comfortable to wear, and you never go to cold climates. These are very low on cm3, so you can just buy those and be happy. But this doesn't work for me: I sometimes visit cold areas, I don't find ankle socks comfortable and prefer something a bit longer, and I need to be comfortable for my long runs. Furthermore, my large foot size means that Uniqlo's one-size-fits-all approach does not work well for me: though I can put the socks on, it often takes a long time to do so (especially after a shower), and the socks rip often.

So I've been exploring various brands to try to find a solution (recently trying CEP and DarnTough). I generally try to find socks that cover the ankle but don't go much higher than that, and I have one pair of long ones for when I go to the snowier places. My sock bag is currently larger than my underwear bag, and only a bit smaller than my T-shirt bag: both a sign of the challenge of finding good socks, and a testament to Uniqlo's amazing Airism T-shirts. Once you do find a pair of socks that you like, ideally you should just buy many copies of the same type. This removes the effort of searching for a matching pair in your bag, and it ensures that if one of your socks rips you don't have to choose between losing the whole pair and wearing mismatched socks.

For shoes, you probably want to limit yourself to at most two: some heavier shoes that you can just wear, and some very cm3-light alternative, such as flip-flops.


There is a key mathematical reason why dressing in layers is a good idea: it lets you cover many possible temperature ranges with fewer clothing items.

Temperature (°C) Clothing
13° +
+ +

You want to keep the T-shirt on in all cases, to protect the other layers from getting dirty. But aside from that, the general rule is: if you choose N clothing items, with levels of warmness spread out across powers of two, then you can be comfortable in \(2^N\) different temperature ranges by binary-encoding the expected temperature in the clothing you wear. For not-so-cold climates, two layers (sweater and jacket) are fine. For a more universal range of climates you'll want three layers: light sweater, heavy sweater and heavy jacket, which can cover \(2^3 = 8\) different temperature ranges all the way from summer to Siberian winter (of course, heavy winter jackets are not easily packable, so you may have to just wear it when you get on the plane).

This layering principle applies not just to upper-wear, but also pants. I have a pair of thin pants plus Uniqlo tights, and I can wear the thin pants alone in warmer climates and put the Uniqlo tights under them in colder climates. The tights also double as pyjamas.

My miscellaneous stuff

The internet constantly yells at me for not having a good microphone. I solved this problem by getting a portable microphone!

My workstation, using the Apogee HypeMIC travel microphone (unfortunately micro-USB, not USBC). A toilet paper roll works great as a stand, but I've also found that having a stand is not really necessary and you can just let the microphone lie down beside your laptop.

Next, my laptop stand. Laptop stands are great for improving your posture. I have two recommendations for laptop stands, one medium-effective but very light on cm3, and one very effective but heavier on cm3.

Nexstand is the one in the picture above. Majextand is the one glued to the bottom of my laptop now:

I have used both, and recommend both. In addition to this I also have another piece of laptop gear: a 20000 mAh laptop-friendly power bank. This adds even more to my laptop's already decent battery life, and makes it generally easy to live on the road.

Now, my medicine bag:

This contains a combination of various life-extension medicines (metformin, ashwagandha, and some vitamins), and covid defense gear: a CO2 meter (CO2 concentration minus 420 roughly gives you how much human-breathed-out air you're breathing in, so it's a good proxy for virus risk), masks, antigen tests and fluvoxamine. The tests were a free care package from the Singapore government, and they happened to be excellent on cm3 so I carry them around. Covid defense and life extension are both fields where the science is rapidly evolving, so don't blindly follow this static list; follow the science yourself or listen to the latest advice of an expert that you do trust. Air filters and far-UVC (especially 222 nm) lamps are also promising covid defense options, and portable versions exist for both.

At this particular time I don't happen to have a first aid kit with me, but in general it's also recommended; plenty of good travel options exist, eg. this.

Finally, mobile data. Generally, you want to make sure you have a phone that supports eSIM. These days, more and more phones do. Wherever you go, you can buy an eSIM for that place online. I personally use Airalo, but there are many options. If you are lazy, you can also just use Google Fi, though in my experience Google Fi's quality and reliability of service tends to be fairly mediocre.

Have some fun!

Not everything that you have needs to be designed around cm3 minimization. For me personally, I have four items that are not particularly cm3 optimized but that I still really enjoy having around.

My laptop bag, bought in an outdoor market in Zambia.


Sweatpants for indoor use, that are either fox-themed or Shiba Inu-themed depending on whom you ask.

Gloves (phone-friendly): I bought the left one for $4 in Mong Kok and the right one for $5 in Chinatown, Toronto back in 2016. By coincidence, I lost different ones from each pair, so the remaining two match. I keep them around as a reminder of the time when money was much more scarce for me.

The more you save space on the boring stuff, the more you can leave some space for a few special items that can bring the most joy to your life.

How to stay sane as a nomad

Many people find the nomad lifestyle to be disorienting, and report feeling comfort from having a "permanent base". I find myself not really having these feelings: I do feel disorientation when I change locations more than once every ~7 days, but as long as I'm in the same place for longer than that, I acclimate and it "feels like home". I can't tell how much of this is my unique difficult-to-replicate personality traits, and how much can be done by anyone. In general, some tips that I recommend are:

How to compromise

Not everyone can survive with just the items I have. You might have some need for heavier clothing that cannot fit inside one backpack. You might be a big nerd in some physical-stuff-dependent field: I know life extension nerds, covid defense nerds, and many more. You might really love your three monitors and keyboard. You might have children.

The 40-liter backpack is in my opinion a truly ideal size if you can manage it: 40 liters lets you carry a week's worth of stuff, and generally all of life's basic necessities, and it's at the same time very carry-friendly: I have never had it rejected from carry-on in all the flights on many kinds of airplane that I have taken it, and when needed I can just barely stuff it under the seat in front of me in a way that looks legit to staff. Once you start going lower than 40 liters, the disadvantages start stacking up and exceeding the marginal upsides. But if 40 liters is not enough for you, there are two natural fallback options:

Either option can get you up to a respectable 80 liters, and still preserve a lot of the benefits of the 40-liter backpack lifestyle. Backpack plus mini-suitcase generally seems to be more popular than the big backpack route. It's up to you to decide which tradeoffs to take, and where your personal values lie!