Ryanair Bag Sizer: What Passes and What Doesn't

Ryanair's bag sizer is the most talked-about piece of metal in budget European aviation. Millions of travellers per year encounter it, many dread it, and a significant number lose money because their bag didn't fit. This guide explains exactly how the sizer works, what bags typically pass and fail, and what to do if yours doesn't make it through.

The Two Ryanair Bag Allowances

Ryanair operates a two-tier bag system. Understanding the difference is essential before you even think about the sizer.

Small personal bag (free for all passengers):

• Maximum size: 40 × 20 × 25 cm
• Goes under the seat in front of you
• Free for everyone — no Priority required
• Handles and wheels included in dimensions

Large cabin bag (Priority Boarding passengers only):

• Maximum size: 55 × 40 × 20 cm
• Goes in the overhead bin
• Requires Priority Boarding (purchased separately or included in Plus/Flexi Plus fares)
• Weighs up to 10 kg
• Handles and wheels included in dimensions

If you don't have Priority Boarding, your large cabin bag will be gate-checked at no charge during busy periods — but this is at Ryanair's discretion. Don't rely on it. If you want that bag in the cabin, buy Priority.

What the Physical Sizer Looks Like

The Ryanair bag sizer is a metal frame bolted to a stand, typically positioned at the boarding gate. The frame is an exact replica of the permitted bag dimensions — you place your bag in the frame and it must fit without forcing or squeezing the frame.

For the large cabin bag, the frame is 55 × 40 × 20 cm. This 20 cm depth is the dimension that catches most travellers. Many mainstream carry-on suitcases are 22–25 cm deep, which is well within US airline norms but solidly outside Ryanair's limit.

The sizer includes a small tray at the bottom to account for wheels and a lip around the top for handles. When measuring your own bag, you should measure to the outermost point of handles and wheels — exactly as the sizer does.

What Bags Typically Fail

Hard-shell bags over 20 cm deep: Any hard suitcase that is 22 cm or deeper in the main compartment will fail. It simply won't compress. The standard "20-inch international carry-on" from brands like Samsonite or American Tourister is typically 22–24 cm deep and will fail.

Overstuffed soft bags: A soft bag that would fit at 80% capacity often fails when packed to bursting. The expansion adds 2–4 cm to each dimension. A 55×40×19 cm bag packed tight becomes a 55×42×23 cm bag — and that fails.

Bags with large external pockets: External laptop pockets, external hydration pockets, or structured external pouches add depth that the empty bag dimension doesn't show. Pack them and measure again before you travel.

Framed backpacks: Backpacks with rigid internal frames or structural stays sit at a fixed depth. A 60L backpack might technically compress to under 20 cm when empty, but its frame won't let it collapse under 20 cm when packed.

What Bags Typically Pass

Purpose-built Ryanair bags: Several manufacturers (Cabin Max, VANGO, Quaechua) sell bags specifically designed for 55×40×20 cm. These pass reliably, including when modestly packed.

Soft roll-aboard bags at 40×20×25 cm: The smaller personal bag allowance of 40×20×25 cm is actually quite generous in two dimensions. A 25 cm depth is comfortable for most soft bags, and many laptop bags and smaller soft cases fit this easily.

Soft duffel bags and backpacks: An unstructured soft bag — a duffel, a stuff sack, a soft tote — can usually be compressed to fit the sizer even if its nominal dimensions are slightly larger. Gate agents often apply moderate physical pressure when checking these. If it goes in with some effort, it usually passes.

Laptop bags and small backpacks: A 20-litre to 30-litre backpack with a laptop compartment will almost always fit the 40×20×25 cm personal item sizer.

Packing Tricks to Get Soft Bags Through

1. Pack strategically — put soft items against the sides Socks, underwear, and light clothing items can be stuffed into corners and edges. These compress when the bag is placed in the sizer. Hard items (shoes, electronics) should go in the middle of the bag, not against the walls.

2. Remove items before the sizer check Ryanair gate agents check the bag as presented. They do not typically make you re-pack. If a jacket, shoes, or laptop are in the bag when you approach the gate, put them on or carry them in your hands. Many travellers walk through the sizer test holding their laptop, then put it back in afterward. This is widely practiced and generally not challenged.

3. Deflate or compress the bag Many soft bags have a compression strap system. Before you get to the gate, cinch every compression strap as tight as possible. This can reduce a 22 cm depth to 19 cm.

4. Under-pack deliberately If you're relying on a bag that's right at the limit, don't pack it full. Leave 20% of the capacity unused and the bag will naturally compress within the sizer.

What Happens If Your Bag Doesn't Fit

If your bag fails the sizer at the gate, Ryanair staff will direct you to pay a hold bag fee before you board. This is significantly more expensive than pre-purchasing:

• Online/app purchase (before check-in closes): €8–€25 depending on route and timing
• At the airport check-in desk: €20–€40
• At the gate: €50–€80 or more

Gate bag fees are deliberately punishing. Ryanair's revenue model depends on this penalty. The bag then travels in the hold and you collect it at the destination carousel.

You cannot negotiate the gate fee. You cannot refuse and try again. If your bag is selected for a sizer check, it passes or it pays.

When Sizer Checks Actually Happen

Not every bag gets checked at every gate. Ryanair staff typically conduct checks when:

• The flight is heavily loaded and overhead space is limited
• They see a bag that looks obviously oversized
• You board without Priority at a heavily enforced boarding gate

On less popular routes or quieter flights, bag checks are rare. On high-volume routes (Dublin–London, Barcelona–London, Madrid–Milan), enforcement is consistent. Don't gamble on a lax gate agent.

The Safe Approach

The safest approach to Ryanair travel is simple: buy a bag that fits 55×40×20 cm (if you want overhead space) or 40×20×25 cm (if you're traveling light), and don't overpack it. The cost of buying a correct bag once is always less than a single gate bag fee.

If you're travelling with only a personal item, the 40×20×25 cm limit is genuinely spacious for a weekend trip. Many experienced Ryanair travellers manage with this allowance alone and never worry about the sizer at all.