Ryanair Backpack Carry-On: How to Actually Use 40x30x20 cm

Ryanair announced on 4 September 2025 that it had finished rolling out bigger bag sizers at all 235 of its European airports, and that the free bag may now measure 40 x 30 x 20 cm. That's 33 percent more than the EU minimum standard of 40 x 30 x 15 cm, which the airline cites in the same release.

Two things in that table matter more than any product pick.

First, 40 x 30 x 20 cm is 24 litres. The old 40 x 20 x 25 cm was 20 litres. Four extra litres sounds like nothing. It's roughly a pair of shoes, or two more t-shirts.

Second, Ryanair names no euro figure for a non-compliant bag. Its own wording is that anyone who fails to comply pays the checked in bag fee at the boarding gate. What that fee actually is, the airline doesn't publish as a single number. Hauptstadtkoffer reports 46 to 80 euros, but that's a secondary source, not a Ryanair tariff. If somebody quotes you an exact figure, ask where it came from.

Which is the real reason you're reading this.

Older backpacks are still marketed at 40 x 20 x 25 cm. Older guides still quote it. Some Amazon titles carry it in the product name. None of that is flatly false, just incomplete, and it breeds a stubborn misunderstanding.

Does a 40 x 20 x 25 cm backpack still fit the new sizer? Yes. Its three edges are 40, 25 and 20 cm. The frame is 40, 30 and 20 cm. Turn it and it slides through with 5 cm to spare on one axis.

The catch: you're giving away 4 litres you already paid for. That's why the outdated number costs you money even though it never triggers a fee.

Here's the part no retailer page gives you. For every backpack in this article I looked up the figure the manufacturer publishes on its own product page, not the one in the Amazon title. Everything below is a manufacturer's stated spec, not our own measurement. On a soft bag the packed size differs from the catalogue size, and there is no public, reliable source for that difference. So you won't find invented precision here.

Where those numbers come from: Cabin Max lists the Metz 20L at height 40 cm, width 25 cm, depth 20 cm, 20 litres and 0.5 kg. The Metz 44L page gives 55 x 40 x 20 cm, 44 litres and 0.7 kg. SKYSPER states 16.9 x 10.3 x 7.4 inches and 1.1 lbs for its 20-litre packs, which converts to 42.9 x 26.2 x 18.8 cm and about 0.5 kg. Both SKYSPER models carry the identical catalogue figure.

Why a 42.9 cm Daypack Fails

The sizer's longest edge is 40 cm. A backpack with a 42.9 cm back panel is 2.9 cm over on that axis, and no other axis can compensate. You can squash a hiking pack across its width. You cannot shorten it: that's where the back padding sits.

So are those two SKYSPER packs junk? Not at all. Just not for this slot. As a daypack at your destination they work well, and with Priority a daypack travels along without drama. Buying one as your free Ryanair carry-on is buying a risk.

For the free slot, the sensible pick in this lineup is the Cabin Max For Ryanair Hand Luggage Backpack 40 x 20 x 25 cm, Travel Backpack, Wizzair Aircraft Bag, Eurowings, Easyjet Vueling, or the plainer base model Cabin Max Travel Backpack 40x20x25 cm - Handgepäck Rucksack für Unter-Sitz Gepäck, perfekt für Condor Economy Zero. Both are Metz variants sharing the same catalogue size, around €25 and €19 on Amazon.de (price snapshot January 2026, prices move).

The foldable SKYSPER 20L Foldable Backpack Ultralight Daypack Waterproof Daypack Travel Backpack Hiking Backpack and the ventilated SKYSPER Lightweight Hiking Backpack Small Backpack with Back Ventilation Trekking Backpack Made of Breathable 3D Air Mesh Polyester are hiking and secondary packs. If you're flying Priority, the Cabin Max Handgepäck Rucksack 55x40x20 cm - 44 Liter Leichter Reiserucksack für Flugzeug Kabinengepäck at 55 x 40 x 20 cm is the one that fills the bigger allowance completely.

Catalogue Size Is Not Packed Size

One thing manufacturer pages always leave out: the stated figure describes the bag empty and lying flat. Stuffed full, the front panel bulges and the depth grows. With only 20 cm of depth in the sizer, that's the axis with the least room.

No reliable, publicly checkable packed measurements exist for these bags. That's why there's no such column in the table above, and why you should be suspicious of any article that hands you one.

For years the claim circulated that the metal frames at the gate were more generous than the official figure. Some forum posts quoted 42 x 20 x 30 cm instead of 40 x 20 x 25 cm.

Those measurements are now scrap paper. Ryanair swapped the sizers at all 235 airports to match the new size. Any tolerance figure produced before September 2025 describes a frame that is physically no longer at the gate.

What hasn't changed: they measure the whole package. Handles, straps, water bottles clipped on the outside. And the airline has no interest in checks getting looser. Since July 2025 staff receive €2.50 instead of €1.50 per oversized bag spotted, with no monthly cap.

Four litres isn't a moving box. But it shifts what a weekend without Priority looks like.

20 litres holds two rolled t-shirts, one pair of trousers, underwear for three days, travel-size toiletries, cables and a power bank. Passport in the front pocket, always reachable. Mind the liquids rules and what's actually allowed in hand luggage too.

The four extra litres cover roughly one pair of flat shoes, or two more tops. Not a 15-inch laptop plus two pairs of sneakers plus camera gear. That was Priority territory before and it still is. Our packing techniques for small carry-ons get more out of either size than any backpack recommendation will.

Priority & 2 Cabin Bags costs €8 to €32 according to Ryanair, depending on route and date. That adds the 10 kg trolley at 55 x 40 x 20 cm.

Do the arithmetic. At €8 on a short hop with three days of luggage, easy call. At €32 in peak season you're often paying more than the fare, and then it's worth checking whether the same route works out cheaper on an airline with a bigger free allowance. Lufthansa and Eurowings count differently. If you're torn between a backpack and a trolley, our hand luggage comparison helps.

For two nights with a 24-litre backpack you don't need Priority.

TikTok and Amazon are full of bags promising they're guaranteed accepted at the gate. €40, sometimes more.

There is no certification. Ryanair checks whether the bag fits the frame, not what label is on it. Holiday Expert tested cheaper alternatives and lands in the same place: the size is what decides.

And since the airline charges only 0.1 percent of passengers, roughly 200,000 out of 200 million according to CEO Michael O'Leary, what you're mainly buying with one of those bags is reassurance. A tape measure does that too.

The useful takeaway here isn't a purchase, it's a number: 40 x 30 x 20 cm. Plan around 40 x 20 x 25 cm and you throw away four litres. Buy a hiking pack with a 42.9 cm back panel for the free slot and you buy a problem.

Tape measure against the bag, longest edge under 40 cm, depth under 20 cm once it's packed. Then the gate is boring, and boring is exactly what you want from Ryanair.