Your backpack is the most important gear decision you'll make
A bad backpack ruins a trip faster than bad weather. Shoulder straps that dig in after 20 minutes. A hip belt that rides up. A bag that's too big to qualify as carry-on, so you're checking it and waiting at the carousel in every airport.
A good backpack, on the other hand, disappears. You forget it's there. You walk through train stations and narrow streets without it catching on things. You board the plane, put it overhead, sit down. No fees, no waiting, no carousel anxiety.
This guide covers how to pick one, what features actually matter, and what's marketing noise.
Size: the only spec that matters
Travel backpacks come in sizes from 20L to 70L. Here's what actually fits in each range:
20-30L (daypack/weekend): Enough for 2-3 days if you pack light. A few changes of clothes, a rain jacket, toiletries. This is the minimalist carry-on option. Fits under airplane seats on most carriers.
30-40L (the carry-on sweet spot): A week's worth of clothes, a laptop, toiletries, and room for a souvenir or two. This is what most travel backpack recommendations center on, and for good reason. It meets carry-on limits on almost every airline.
40-50L (extended travel): Two weeks to a month. Fits carry-on dimensions on most airlines but will be heavy enough that budget carriers might make you check it by weight. Good for colder destinations where bulky layers eat space.
50-70L (backpacking trips): Multi-week to multi-month trips with camping gear, or cold-weather trips where you need heavy jackets and boots. You're checking this. Plan accordingly.
For most trips, 35-40L is the right size. It's carry-on legal, holds enough for two weeks if you do laundry, and doesn't tempt you to overpack. Our packing list tool can help you figure out exactly what you need to bring.
Carry-on sizing: the real numbers
Airlines measure carry-on bags differently, and the "standard" size varies more than you'd think.
- Most US carriers: 22" x 14" x 9" (56 x 36 x 23 cm)
- European carriers (Ryanair, EasyJet): Smaller. Ryanair's paid carry-on is 21.7" x 15.7" x 7.9". Their free personal item is tiny.
- Asian budget carriers (AirAsia, Scoot): Usually 22" x 14" x 10" but with strict 7-10kg weight limits.
If you're flying budget airlines in Europe or Asia, dimensions matter less than weight. A 40L bag packed to 10kg is fine. The same bag at 15kg will get flagged. Pack light clothes and leave the "just in case" items at home.
A backpack has a soft shape, which helps. Unlike a hard-shell suitcase, you can squeeze it into overhead bins and sizers. That flexibility is worth more than a few extra liters of capacity.
Features that are actually worth paying for
Hip belt with padding. Transfers weight from your shoulders to your hips. Non-negotiable for anything over 30L. A good hip belt is the difference between walking comfortably for hours and wanting to set the bag on fire by noon.
Front-loading (clamshell) opening. Top-loaders are for hiking. Travel backpacks should open flat like a suitcase so you can see everything and pack efficiently. This is the single feature that separates a "travel backpack" from a hiking pack.
Laptop sleeve. Padded, suspended (doesn't touch the ground when you set the bag down), and accessible without opening the main compartment. You'll use this at airport security and cafes.
Compression straps. Cinch the bag down when it's not full. Makes a 40L bag act like a 30L on shorter trips. Also keeps contents from shifting.
Lockable zippers. Not for serious security (a knife defeats any zipper), but for deterring opportunistic hands on crowded trains and buses. TSA-friendly locks that fit through the zipper pulls.
Features you can skip
Built-in rain cover. A $5 pack cover from Amazon does the same thing and weighs less. Or just use a plastic bag.
Shoe compartment. Sounds useful, takes up volume you'll want for other things. Put your shoes in a plastic bag and pack them at the bottom.
USB charging port. A gimmick. You still need a battery pack inside. Just put the battery pack in an outside pocket with a cable.
Anti-theft features. Hidden zippers, slash-proof fabric, steel cables. These add weight and cost for marginal security. A simple cable lock and common sense are enough.
"Expandable" capacity. A 35L bag that expands to 45L means a 45L bag that compresses to 35L. It'll be heavy and oversized at both settings. Pick one size.
How to get the right fit
Backpack fit is about torso length, not height. A 5'4" person with a long torso and a 6'2" person with a short torso might wear the same pack size.
To measure your torso: have someone measure from the bony bump at the base of your neck (C7 vertebra) to the top of your hip bones (iliac crest). That number in inches corresponds to the pack's torso size:
- Under 17": Small/XS
- 17-19": Medium/Regular (most people)
- 19"+: Large/Tall
The shoulder straps should wrap around your shoulders without gaps. The hip belt should sit on top of your hip bones, not your waist. The load lifter straps (the small straps above the shoulder straps) should pull the top of the pack toward your body at about a 45-degree angle.
Try the pack on with weight in it. An empty pack fits everyone. A 25-pound pack shows you where the problems are.
How your destination changes what you need
Not every trip needs the same bag. What you carry to Bali is different from what you carry to Lisbon in November.
Tropical destinations (Bali, Bangkok, Phuket): 30-35L is plenty. Clothes are light and compact. You need less of everything. Prioritize ventilation on the back panel.
European cities (Lisbon, Athens, Istanbul): 35-40L. You'll want layers and slightly nicer clothes for restaurants and cultural sites. A separate day bag or packable tote is useful.
Cold-weather trips: 40-50L minimum. Puffy jackets, thermal layers, and warm accessories eat volume fast. Compression packing cubes become essential.
Multi-stop trips: Go smaller than you think. You'll carry that bag on buses, through train stations, and up hostel stairs. Every liter you don't fill is a liter you don't carry.
Use our packing list tool to generate a weather-appropriate list for your specific destination and dates. It'll help you figure out the right bag size.
Packing cubes: yes, they're worth it
Packing cubes seem like an unnecessary accessory until you use them. Then you can't go back.
Compression cubes let you fit more into less space by squeezing out air. Regular cubes keep things organized so you're not digging through your entire bag for socks.
A basic setup: one large cube for clothes, one medium for underwear/socks, one small for electronics and cables. Total cost: $15-25 for a set. They make a $60 backpack feel like a $200 one.
Roll your clothes instead of folding. Fits more, wrinkles less. Pack heavy items (shoes, toiletries) at the bottom near your hips. Light items (rain jacket, hat) at the top for easy access.
What to spend
Under $50: Amazon basics. Serviceable for occasional weekend trips. Won't last if you travel regularly. Hip belts are flimsy or nonexistent.
$50-100: The value zone. Several good options with decent hip belts, front-loading, and laptop sleeves. This is where most people should buy.
$100-200: Premium materials, better zippers, more comfortable suspension systems. Worth it if you travel more than twice a year.
$200+: Expedition-grade or specialty brands. Goruck, Tortuga, Peak Design territory. Built to last a decade but overkill for casual travelers.
Here's the honest take: a $75 backpack gets you 90% of what a $200 backpack offers. The last 10% is nicer fabric, smoother zippers, and a slightly better fit. It matters on a 6-month trip. It doesn't matter on a 2-week vacation.