Hi, I had a flight to and from Venice , however my flight back I had to pay for my bag 29 euro, the same bag I took correct size that I left Paris with. My bag was as per below. This was not a nice experience. It can be a maximum size of 45 x 36 x 20 cm (including any handles or wheels) and needs to fit under the seat in front of you. That should be enough to bring all the essentials for your journey or for a short trip. Your bag can weigh up to 15kg,