How to choose a luggage bag size?

Choosing the appropriate luggage size requires comprehensive consideration of various factors, including itinerary, travel days, personal preferences, and physical conditions. Based on the itinerary and travel days, we can roughly determine the size of the luggage bag needed. Generally speaking, for short trips of one to two days, a small luggage bag with a capacity of 30-40 liters can be chosen; For a 3-5 day trip, you can choose a medium-sized luggage bag with a capacity of 40-65 liters; For long-distance travel exceeding 5 days, you can choose large suitcases with a capacity of 65-90 liters or even larger. Of course, the specific choice also needs to be measured based on one's personal preferences and physical conditions.