What size bag should you buy?
The single bag size that fits the most airlines in each group — worked out from real limits, so you buy once and travel free.
Sizes shown as largest × middle × shortest side (orientation doesn’t matter for the sizer).
Best cabin bag size for Europe
One cabin bag that clears the overhead-bin limit on European airlines.
35 × 30 × 18 cmfits all 49
Best free personal item size for Europe
The largest under-seat bag that flies free across European airlines.
40 × 30 × 20 cmfits all 8
Best carry-on size for US airlines
The carry-on size that fits the overhead bin across US airlines.
55 × 35 × 22 cmfits all 13
Best free personal item size for US airlines
The under-seat personal item that’s free on every US airline — including Spirit and Frontier.
41 × 33 × 18 cmfits all 6
Best bag size for Ryanair, Wizz Air & easyJet
Flying Europe’s big three low-cost airlines? One free size covers all.
40 × 30 × 20 cmfits all 3
Best free bag size for budget airlines
Fly hand-luggage-only across Europe’s low-cost airlines without paying for a cabin bag.
40 × 30 × 20 cmfits all 10
Best carry-on size that fits worldwide
The safest cabin bag size for international travel across every airline we track.
35 × 30 × 18 cmfits all 151