Carry-on bags stay with you in the cabin. Most airlines set the size around 55 by 40 by 20 centimetres, though a few allow slightly more. Weight limits usually fall between 7 and 10 kilograms. The bag must fit in the overhead bin or under the seat in front. Soft bags sometimes squeeze in more easily than rigid ones.

Checked bags travel in the hold. The standard free allowance is often one bag of 23 kilograms for economy tickets. Some fares include none at all. A second bag or any weight over the limit brings an extra fee. The fee rises if you pay at the airport counter instead of online in advance.

Extra bags become necessary when the free allowance is used up or when the ticket type includes no free checked bag. Sports equipment, musical instruments and oversized items almost always cost more. The price depends on the route and how early you add the bag. Paying online days before departure is cheaper than doing it at the desk on the day of travel.

To avoid unexpected charges, weigh every bag at home with a reliable scale. Leave a small margin under the limit because airport scales can read a kilo higher. Measure the dimensions including wheels and handles. If the bag sits close to the maximum, remove one or two items and move them to the carry-on if space allows.

Check the exact rules for the ticket you bought. Fare conditions list the free allowance clearly. Screenshots or a saved copy of those conditions help if a discussion starts at the counter. Some tickets look cheap until the baggage fees appear, so the total cost only becomes clear after adding the bags.

At the airport the staff may ask to weigh the carry-on as well. If it exceeds the limit they can request it be checked and charged. Keeping the cabin bag light and within size avoids that conversation. Liquids and restricted items already follow their own rules, so packing them correctly also prevents delays that sometimes lead to extra handling fees.

A short review of the baggage page for the specific flight the day before travel catches most surprises. Once the bags sit under the limits and any extra pieces are paid in advance, the check-in process stays simple and the total cost remains the one you planned.