The answer to this question usually depends on how much and how well do you pack. If packed well, you can fit enough items to keep you going for 5-7 days abroad in a large cabin suitcase that usually measures 55 cm in height and has a capacity of up to 45 litres. If you tend to overpack, you will need a checked-in suitcase that has a capacity of atleast 60 to 90 liters. This guide on how to pack a suitcase will tell you more about optimizing your packing space.