For your 2026 travels with Ryanair, the permitted dimensions for a free small personal bag are 40 x 30 x 20 cm. This bag must be able to fit completely under the seat in front of you. If you have purchased "Priority & 2 Cabin Bags," you are additionally allowed a larger 10kg cabin bag with maximum dimensions of 55 x 40 x 20 cm, which goes into the overhead locker. Ryanair is notoriously strict about these limits and uses metal sizers at the boarding gate to verify compliance. If your bag does not fit into the sizer, you will be charged a significant "gate bag fee," which can range from €45 to €70 depending on the route. To ensure a smooth journey, it is a high-fidelity best practice to measure your luggage including wheels and handles, and consider using a soft-sided bag that can be compressed if necessary to fit the rigid dimensions of the airport sizer.