How to Avoid Fees Traveling with Only an Underseat Cabin Bag / Personal Item — An All-Airline Guide and Comparison of Restrictions

Your Guide

Mose Hayward

Travel Nerd

We’ve collected official up-to-date sizing restrictions for personal items, a.k.a. cabin bags, that are intended to go under the seat in front of you when you fly. These are always free, included with your flight ticket.

We have focused on the restrictions from the (often “budget”) airlines that allow only an underseat cabin bag. That is, they charge you extra for even a full-sized carry-on luggage piece, which would be placed in an overhead bin.

Airlines that include only an underseat bag in the most basic fare tend to offer cheap tickets—but you must be particularly careful about your bag’s size or you end up paying more.

So, armed with a bit of knowledge, you can fly light with a single bag that’s exactly the right size, maximizing your carrying capacity without risking extra fees on top of your plane ticket.

If you just want to know which airline is the most restrictive for cabin bags, you’ll see in our comparison table below that it’s RyanAir. Get a bag that meets those restrictions and you’ll pretty much be fine anywhere you fly. We have bag recommendations below as well—the durable and fairly priced underseat cabin bags that we have actually used on RyanAir and other budget airlines.

Table Of Contents

Airlines' Size Limits on Underseat Cabin Bags — Ordered from Smallest to Largest
Our Recommendations for Underseat Cabin Bags that Avoid Fees
Why Seek to Maximize the Carrying Space in an Underseat Bag?
Frequently Asked Questions on Travel with Underseat Cabin Bags

Our road updates of this article

This article was first published on October 15, 2024. Updated on November 12, 2024 with some more information and FAQs.

Airlines’ Size Limits on Underseat Cabin Bags — Ordered from Smallest to Largest

The following are the most popular world airlines that allow you to carry only a personal item with the most basic fare. That means flying cheap if you don’t take a full-sized carry-on.

So the table below shows what you can get away with carrying without paying anything extra on top of your ticket price. This is a general guide for reference and to get an idea for what sizes are worthwhile to purchase depending on what airlines you tend to take.

The safest bet is to get a 20-30L bag like those recommended further below that is soft and thus can be squished into a smaller sizer if absolutely necessary for the most restrictive and strict airlines, keeping in mind that such checks of small-looking bags don’t actually usually happen.

The Golden Rules of Avoiding Fees on Carry-Ons

Squishy bags can fit in sizers: Bags that have some give and are not overstuffed tend to be fine, even if they’re a bit over the official limits.
Suitcases with wheels are the most likely to be scrutinized. Backpacks of the same size tend to not be checked as often.
We’ve never seen a scale for weighing carry-ons at the gate. However, if you’re checking luggage it’s possible that the weight of your carry-ons will also be verified at the check-in counter, where there is generally a scale.
Most of the time, airline staff doesn’t have the time to carefully check bags during boarding. They’ll maybe flag roller carry-ons used by people whose ticket category is for traveling with only an underseat cabin bag, but they’re unlikely to check more carefully than that in most cases. If you’re travelling with a bag that’s just a few centimeters off of the requirements, it’s rare that you’ll pay an extra fee at the gate, though it can happen.

Our Recommendations for Underseat Cabin Bags that Avoid Fees

Osprey Ozone Laptop Backpack on my back, seen from the side; this is my personal favorite at the moment

All of the below bags are recommended for travelling in any restrictive budget airline, including all of those in our chart above. Certain dimensions for some of these bags are actually slightly larger than the official cabin bag/personal item limits, but we nevertheless travel with them, even on the most restrictive like RyanAir and United Airlines, and we recommend these bags for any of them.

That’s because:

These bags are flexible fabric and so, if not overstuffed, can easily fit in the sizers at airports if you happen to be checked at the gate by stickler employees.
They are also small-looking and unassuming and so don’t draw scrutiny to begin with.

CabinZero Classic Cabin Backpack 28L

The super-affordable-but-durable, basic option that squeaks past as a cabin bag on any flight, truly maximizing what you can carry within the restrictions in a sturdy fabric box you wear on your back.

PROS: Streamlined and uncomplicated, without extra features to take up space or bring up the cost. Excellent construction with durable, lightweight 600D polyester and large YKK zippers. Definitely the best quality build available at this low price. Many available colors. Basic organizational pockets inside and on the front flap.

CONS: Very basic, without substantial padding on the laptop sleeve, ergonomic back support, or a sternum strap.

Check on Amazon

Check on CabinZero

Our full review of the CabinZero Classic 28L is here.

Osprey Transporter Boarding Bag 20L

The sleek, ultra-weatherproof shoulder bag for keeping things simple on the outside and well-organized on the inside.

PROS: Extremely water-repellent coating on a smart, very well-built bag. A roomy main storage compartment and laptop sleeve and side organizational inside pockets for keeping everything easily at hand.

CONS: Over-the-shoulder carry is perfect for having electronics and boarding passes at hand, but not ideal for trips with lots of walking. The padded strap is extremely comfortable, though.

Check on Amazon

See our full review of the Osprey Transporter Boarding Bag 20L.

Osprey Ozone Laptop Backpack 28L

The fancy, full-featured, and yet exceptionally lightweight bag that’s perfect for one-bagging as a minimalist with only a cabin bag for weeks or months of travel. I’ve done it with this on my back and loved it.

PROS: Lightweight-but-durable materials and construction. Excellent protection for carrying a laptop with a large sleeve that hangs just above the bottom. Comfortable for long walks with breathable padding and straps and a sternum strap. Smart organizational pockets throughout. Structured form but still squishy enough to fit in all airlines’ cabin bag sizers if not overpacked.

CONS: Somewhat pricier (though worth it, for frequent travel). Also, this has kept my stuff perfectly dry in the rain, but it’s not completely waterproof (for that, check out the heavier and heavier-duty Osprey Transporter Waterproof 30L.

Check on Amazon

Here is our full review of the Osprey Ozone Laptop Backpack 28L.

The above Osprey bags are also ideal when travelling heavier with wheeled luggage, as they have a luggage handle pass-through sleeve that allows them to be securely placed on top of the wheeled luggage and rolled. The Cabin Zero bag does not have a luggage pass-through sleeve.

Why Seek to Maximize the Carrying Space in an Underseat Bag?

Here I am boarding a Vueling budget flight in Barcelona with the Osprey Transporter Boarding Bag 20L mentioned above.

For years I’ve opted for full-size wheeled carry-on backpacks or, on occasion, even a larger (checked) wheeled backpack. But for certain destinations flights can’t practically be avoided and the cheapest ones are now often underseat-bag-only, unless you want to pay a supplement that can cost as much as the flight itself.

This makes seeking out an underseat bag or personal item that maximizes the bit of allowed space a worthwhile endeavor.

And it’s worthwhile in any case to travel as light and minimally as possible to improve your experiences. A good minimalist packing list has just the essentials you need, with the knowledge that people generally don’t use half of what they pack and those just-in-case items can almost always be picked up if needed when on the road.

Airline baggage sizers are just one small subset of the horrors inflicted on us during air travel—but by choosing the right carry-ons, they’re at least one of the few things that we can plan for. If we get the right bag, we don’t have to worry about paying extra for luggage and can get serious savings on flights.

Frequently Asked Questions on Travel with Underseat Cabin Bags

What are the general size limits for underseat bags on most airlines?

There is no general rule as each airline makes up its own limits. What we learned from creating the above table of underseat-bag limits is that generally the upper limit is 20-30L, though it can go all the way up to 40L.
The smallest dimension limits are 38 cm (Norwegian) by 25 cm (Ryanair and United Airlines) by 20 cm (many airlines).
Generally, if you get a bag made of flexible material in the 20-30L range it will have some give and be able to be stuffed into a sizer for any airline.

What are the cabin bag restrictions for international flights?

As with national flights, it depends on the airline; there are no general rules for international flights. It’s best to check the rules for the specific airlines above.

Which airline has the most smallest cabin bag restriction?

In our searching of the limits for all popular airlines that allow only one free personal item or cabin bag that goes under the seat in front of you, the most restrictive was RyanAir, with its limit of 20L and 40 x 25 x 20 cm. / 16 x 10 x 8 in. RyanAir does not always enforce this carefully; most people do not get checked. But there is always a risk of a fee at the gate of about €30-70.

Can a backpack count as a personal item on a flight?

Yes, airlines allow you to take a small backpack as a personal item or underseat cabin bag, as long as it fits underneath the seat in front of you, complying with their particular size restrictions (listed per airline in the table further up on this page).

What is the difference between a “carry-on” and a “personal item” or “underseat cabin bag”?

A carry-on is any luggage that is not checked (checked luggage is left at the check-in counter and placed in the airplane’s underbelly). A carry-on can be for example a small roller suitcase or a backpack. It generally gets placed in the overhead compartments and you are expected to not pack so heavy that they can’t lift it and put it there yourself (though employees or other passengers will generally help in such a situation).
What airlines variously call an underseat cabin bag or personal item is a smaller bag or purse that should fit under the seat in front of you.
Your particular airline and ticket type may include a single carry-on, a carry-on plus a personal item, or only a personal item.

Can an underseat cabin bag or personal item have wheels?

Usually since these bags are smaller and lighter they don’t have wheels, but there is nothing prohibiting you from using a wheeled option. Here, for example, is one good rolling personal item for flights. See also our coverage of rolling laptop bags or rolling women’s laptop bags and purses).
If you do choose wheels, be very attentive to the size restrictions as wheeled bags necessarily have more rigid structures and are thus more complicated to fit into bag limit sizers. You also lose some internal storage space to the wheel housing.
Wheeled luggage is also much more likely than backpacks to draw attention at the gate and be subject to checks as to whether it actually fits the size limits.

What are generally the weight limits for underseat carry-on luggage?

Among the airlines that only allow you to take a personal item/underseat bag included in your ticket (and make you pay extra for a full-size carry-on suitcase), very few have weight restrictions on that underseat bag. For those that do, it is 10 kg. (Wizz Air, Transavia, and JetSMART) and 15 kg. (EasyJet).
That said, I have flown all of these airlines except for JetSMART and I have never seen a scale for weighing carry-ons at the boarding gates at these or any other airline. Bag sizers are sometimes used but never scales. It is possible that your carry-ons can be weighed at check-in counters, but if you’re flying carry-on only you generally do not visit the check-in counter but rather check in via an app or online.
I have also seen limits of 8 kg. on some carry-ons for other airlines. It is very difficult, even for minimalist one-baggers, to meet 8 or 10 kg. limits but fortunately these are rarely enforced. It helps to be using bags made of lightweight material like those we recommend here.

Do I really have to put personal items under the seat in front of me?

Often, especially on full flights, you are required to use the space under the seat in front of you for your personal item, and leave the overhead space for larger (often paid) carry-on luggage. While this somewhat reduces your leg room, it does have the advantage of keeping your valuables as well as any electronics and reading material you need nearby during the flight.