A small underseat bag is now the entire free luggage allowance on many basic fares, which makes a few centimetres the difference between an easy boarding and a gate charge. The best bag is not simply the largest: it fits the operating airline’s current sizer, carries comfortably when full and gives travel documents a place you can reach without opening the main compartment.
The right under seat cabin bag depends on the strictest airline in the itinerary. Under seat luggage that works for easyJet may be too large for Ryanair or Wizz Air, while a soft personal item bag can exceed its listed dimensions when every pocket is filled.
Retailers use both “underseat” and “under seat”. In this guide, an underseat cabin bag or underseat bag means cabin luggage designed to fit beneath the seat in front, within the operating airline’s stated limit. The wording on a product page is never proof of compliance.
Current UK airline under-seat limits
| Airline | Small bag maximum | Important note |
|---|---|---|
| Ryanair | 40 × 30 × 20cm | One small personal bag on all fares |
| easyJet | 45 × 36 × 20cm | Up to 15kg; passenger must carry it |
| Wizz Air | 40 × 30 × 20cm | Free carry-on bag; larger trolley requires Priority |
| British Airways | 40 × 30 × 15cm | Personal handbag/backpack limit; BA also lists a larger hand-luggage allowance |
| Jet2 | 40 × 30 × 20cm | Small under-seat bag in addition to standard 10kg hand luggage |
These measurements come from the current first-party baggage pages for Ryanair, easyJet, Wizz Air, British Airways and Jet2 on 1 September 2026. Rules, fare entitlements and enforcement can change. Check the airline operating each flight—not only the company that sold the ticket.
How we selected underseat cabin bags and cabin luggage
Every pick has current manufacturer dimensions and a clearly described capacity or use. We compared the complete external measurement, carrying format, empty weight, access and organisation. The recommendations are based on published specifications rather than a claim of new hands-on testing.
We split the list around two practical size families. Bags at or below 40 × 30 × 20cm target Ryanair, Wizz Air and the Jet2 small-bag limit. Bags around 45 × 36 × 20cm exploit easyJet’s larger free allowance but will not fit stricter sizers. Soft fabric can bulge, and wheels, handles and bottle pockets still count, so no bag name is a boarding guarantee.
The shortlist includes underseat cabin bags for backpack, duffle and wheeled preferences. Every underseat cabin option keeps travel documents within easy reach, but the balance of packing space, smart compartments and carrying comfort differs. Check the airline and fare before deciding which underseat bag format offers the best value.
Seven of the best underseat cabin bags
1. CabinZero Classic Backpack 28L — best overall
The CabinZero Classic 28L measures 39 × 29.5 × 20cm and weighs a listed 600g. That sits just inside the current 40 × 30 × 20cm box used by Ryanair and Wizz Air, while using a rectangular body that packs more efficiently than a rounded daypack.
A clamshell opening, internal straps, suspended laptop sleeve, front quick-access pocket and top and side handles make it work like a soft suitcase. Shoulder straps provide the main carry, with side compression straps to control the load. A 15.6-inch device may fit the sleeve, but a large laptop pushes hard against the exact sizer dimensions and consumes a meaningful share of a short-trip allowance.
2. Cabin Max Metz 24L — best budget backpack
Cabin Max’s current Metz range includes a 24-litre version measuring 40 × 30 × 20cm, designed around the present Ryanair and Wizz Air free-bag envelope. It opens like a suitcase, with a large uncomplicated main compartment that favours packing cubes over a maze of small pockets.
The exact-size shape makes good use of the allowance, but it removes the safety margin offered by CabinZero. Soft clothing should stay within the seams; a bulging zip panel can make a nominally compliant bag too deep. Check that you have selected the 24L 40 × 30 × 20cm model, because the Metz family also includes versions for other airlines and overhead allowances.
3. Aerolite 24L Cabin Backpack — best exact-fit alternative
Aerolite lists a 40 × 30 × 20cm, 24-litre backpack in its current personal-item range. The format uses the full newer Ryanair and Wizz Air dimensions and is also smaller than easyJet’s allowance. A luggage strap and internal organisation make it a practical airport-to-hotel bag.
Aerolite sells several products with very similar names, including older 40 × 25 × 20cm styles and wheeled models. Read the specification beside the exact colour and variant in the basket. A soft 24L backpack can hold a surprising amount, but the volume calculation assumes a perfect box; padding, rounded corners and pocket construction reduce the usable figure.
4. Samsonite Biz2go Duffle Bag / Backpack XS — best business hybrid
The Samsonite Biz2go XS measures 25 × 40 × 20cm—the same three limits in a rotated orientation—and provides 23 litres at a listed 0.9kg. It can be carried as a duffle or backpack, with a sternum strap, top and side handles, two front pockets and a smart sleeve for stacking on larger luggage.
Samsonite specifies water-resistant fabric and internal organisation, while recycled PET forms the listed outer fabric and lining. The business styling and quick pockets suit a laptop-and-clothes mix, although 0.9kg takes a larger bite from a personal-item allowance than a basic soft backpack. Pack to the 40cm side and keep the duffle handles tucked during a sizer check.
5. Osprey Daylite 26+6 — best easyJet backpack
Osprey’s Daylite 26+6 measures 43 × 33 × 16cm unexpanded, provides 26 litres and weighs a listed 0.84kg. Those dimensions sit within easyJet’s current 45 × 36 × 20cm small-bag allowance, but exceed the height and width of the 40 × 30 × 20cm group.
The AirScape back panel, padded harness and sternum strap make it the comfort pick for longer walks between stations and accommodation. It also has a clamshell opening, laptop sleeve, trolley pass-through, multiple grab handles and bottle pockets. Opening the expansion zip adds six litres and about 5cm of depth, taking it beyond easyJet’s 20cm small-bag limit; leave it closed for under-seat use.
6. Travel Hack Hybrid — best easyJet backpack with wheels
The Travel Hack Hybrid, made with Cabin Max, converts between a trolley and backpack. Its published dimensions are 45 × 36 × 20cm with a 30-litre capacity, matching easyJet’s maximum small under-seat bag measurement. A suitcase-style opening, laptop pocket, organiser and bottle holder support a full weekend load.
Wheels make airport movement easy but add weight and occupy internal space. Backpack straps on a wheeled bag also sit against a firmer frame than a purpose-built hiking harness. Most importantly, 45 × 36 × 20cm is too large for the strict 40 × 30 × 20cm group. This is an airline-specific choice, not a one-bag solution for every booking.
7. Samsonite Ecodiver Wheeled Underseater — best premium wheeled bag
The Samsonite Ecodiver Wheeled Underseater measures 45 × 36 × 20cm, holds a listed 30 litres and weighs 2kg. Samsonite presents it specifically as an easyJet-sized underseater, with two wheels, a double-tube handle, water-resistant coated fabric, external access and internal packing straps.
At 2kg it is the heaviest pick here, but the integrated wheels remove that load from your shoulders across long terminals. The soft duffle form is more forgiving in hotel rooms than a hard shell, while the frame still consumes packing space. It is unsuitable for 40 × 30 × 20cm personal-item limits and may leave less foot room than a slim backpack even when accepted.
How to choose an underseat bag for carry on
Buy for the strictest airline you use regularly
If one trip combines Ryanair outbound and easyJet return, the smaller 40 × 30 × 20cm limit controls the whole itinerary unless you pay for extra luggage. A 45 × 36 × 20cm bag may feel more versatile in the shop but creates a fee risk on the strict leg. British Airways’ listed 40 × 30 × 15cm personal item is shallower again, although its fare structure also includes a separate overhead bag; read the full entitlement for your ticket.
Measure the packed bag
Manufacturers quote nominal external dimensions, usually with an empty bag. Pack as you intend to travel, close every expansion zip, load the laptop and measure the widest points including wheels, handles and stuffed pockets. A cardboard template cut to the airline limit is a useful home check. Soft sides help only if the contents can compress without damaging anything.
Balance litres against carrying comfort
A theoretical 24-litre box is enough for a careful two- or three-night wardrobe, toiletries within security rules, chargers and a small device. Winter shoes, camera equipment or a second laptop change the equation. A bag with a shaped back panel and padded straps may sacrifice a litre but feel far better over a one-kilometre walk.
Smart compartments and easy access
Passport, phone, boarding pass, liquids and charging cable should be reachable without exposing the clothing compartment. One flat front pocket and one internal valuables pocket are usually enough. Deep organisers encourage duplication and eat volume. Bottle pockets count within the airline width when filled, so move a large bottle into the main bag before boarding.
Choose wheels only for the right route
Wheeled underseaters work brilliantly through airports and smooth city hotels. They are awkward on cobbles, station stairs and long pavement transfers, and the frame reduces internal space. Backpack-wheeled hybrids compromise on both harness and wheel weight but can be useful when mobility needs change through the journey.
Compare underseat luggage formats and storage
An underseat suitcase with smooth rolling wheels suits long airport concourses, while a backpack or rucksack handles stairs and uneven streets more easily. A tote is simple but concentrates weight on one shoulder. Whichever format you choose, inspect durable materials, zip guards, handle attachments and exterior pockets. Wheels and rigid frames improve manoeuvrability but reduce packing space and add empty weight.
Budget airlines and budget carriers do not share one universal rule. Ryanair and Wizz Air currently use the same headline dimensions for the free small item, while easyJet allows a larger shape; other airlines pair a personal item with overhead locker luggage. Double-check the operating carrier, fare and size restrictions before every flight. That is the reliable way to avoid extra luggage fees, because a bag specifically designed for one airline may fail another sizer.
For short trips, pack efficiently around the items that need easy access: travel documents, liquids, medication, laptop and chargers. Keep clothing in one compact cube and toiletries in a sealed pouch. On longer journeys, an underseat bag may work better beside a larger case than as the only bag. When it sits beneath the seat in front, leave the top pocket within arm’s reach without letting the packed body reduce all of your foot room.
A realistic two-night packing list
- Two lightweight tops, one spare bottom layer and underwear
- Sleepwear and a compressible mid-layer
- Compact wash kit and compliant liquids bag
- Phone, charger, travel adaptor and small power bank
- Medication, documents and a reusable empty water bottle
- Laptop or tablet only when genuinely needed
- One small packing cube and a thin laundry bag
Wear the bulkiest shoes and coat. Avoid filling every pocket at home; the spare space absorbs a packed lunch, wet umbrella or small purchase. If the bag is difficult to close on the bed, it is unlikely to become easier in a boarding queue.
Questions about underseat bags and extra fees
Are under seat cabin bags the same as personal items?
Airlines use different labels for the small bag included on a basic fare. “Personal item”, “small bag” and “under seat bag” can describe the same allowance, but the published dimensions decide what is accepted. Read the operator’s baggage page for every flight and do not assume a product label overrides the airline’s sizer.
In practical terms, personal items and underseat bags need the same checks: measure every side, include wheels and handles, and keep an eye on the packed shape. Compact bags that fit beneath one seat can still breach another carrier’s limit. A small safety margin helps avoid extra fees when a soft panel bulges.
What size is an easyJet under seat bag?
easyJet currently lists a maximum of 45 × 36 × 20cm for the free small-bag allowance, including handles and wheels. That is larger than the current 40 × 30 × 20cm allowance used by Ryanair and Wizz Air. An easyJet under seat bag built to the full limit is therefore not a universal low-cost-airline option, and the operating carrier’s latest rule should always be checked.
Can under seat luggage have wheels?
Yes, provided the complete packed dimensions fit the allowance. Wheels and a telescopic handle add weight and occupy internal volume, but they can make a long terminal much easier. A wheeled personal item bag is less convenient on stairs and may reduce foot space once stowed, so choose it for the whole route rather than the airport alone.
How do you measure a soft travel bag?
Pack the bag normally, close expansion zips, fill external pockets as they will be used and measure the widest points. Include handles that do not fold flat, wheel housings and a filled bottle pocket. Test all three dimensions against a cardboard template or home-made box, then leave a little margin for fabric that shifts in transit.
Can a personal item bag carry liquids and a laptop?
It can, but security rules and airline bag limits are separate. Keep the liquids pouch and laptop accessible for screening without overloading the front panel. A thick device plus a charger can consume several litres and push a soft under seat cabin bag beyond its nominal depth, so measure again after electronics are added.
How can you avoid extra fees at the gate?
Double-check the free carry on allowance for the operating airline, measure the packed bag and close every expansion zip. Do not hang a coat, neck pillow or shopping bag from the outside unless the fare allows another item. The safest underseat cabin bags leave a little room for the fabric to compress into the sizer without forcing fragile belongings.
Which underseat travel bag is best for you?
CabinZero Classic 28L is the strongest all-rounder for current 40 × 30 × 20cm limits; Cabin Max Metz is the simple budget choice; Aerolite offers another exact-size layout; and Samsonite Biz2go brings better business organisation. For easyJet, choose Osprey Daylite 26+6 if you will carry the bag, Travel Hack Hybrid if you want a convertible trolley, or Samsonite Ecodiver for a more substantial wheeled underseater.
For the inside of the bag, our packing-cube comparison explains which organisers earn their space. The Akkeron Hotels guide index collects the rest of our current hotel and travel advice.
Whatever you buy, recheck the allowance inside the airline app before departure and measure the bag when full. A compliant label is helpful. The packed dimensions—and the fare you actually booked—are what count at the gate.