30-50 liters: In general, luggage that has a capacity of about 50 liters or less is sufficient for a weekend trip. There are lots of carry-on duffels, packs and bags in this size range to choose from. 50-75 liters: For a trip that lasts one to two weeks, many people jump up to a bag in this range.

A "good" suitcase capacity depends entirely on the length of your trip and your personal packing style, but for most travelers in 2026, the sweet spot for a carry-on bag is 35 to 45 liters. This size generally fits within most international airline "overhead" requirements (roughly 22x14x9 inches) while providing enough space for a 3- to 5-day trip. For a medium checked bag intended for a 1- to 2-week journey, a capacity of 65 to 75 liters is considered ideal; it is large enough to hold multiple outfits and shoes but small enough to stay under the standard 50lb (23kg) weight limit when packed reasonably. For long-term travel or moving, a large checked bag can go up to 90 to 110 liters, though these often risk incurring "oversized" or "overweight" fees. When choosing a capacity, it is also important to consider the "expansion" feature found on many modern suitcases, which can add about 10–15% more volume—perfect for bringing home souvenirs—but may push the bag beyond the legal dimensions for a carry-on or standard checked item.