While every airline differs, the "international standard" for hand luggage in 2026 is approximately 55 x 40 x 23 cm (22 x 16 x 9 inches). This size is designed to fit into the overhead bins of most narrow-body aircraft like the Boeing 737 or Airbus A320. Weight limits vary significantly: "Full-service" carriers like United, Delta, or British Airways often have generous weight limits (up to 23kg on BA), whereas "Low-cost" carriers like Ryanair, EasyJet, or AirAsia are much stricter, often limiting you to 7kg (15 lbs). Additionally, most airlines allow one small "personal item" (like a laptop bag or purse) that must fit under the seat in front of you. In 2026, many budget airlines have moved to a "Basic Economy" model where even the standard overhead bin bag requires a paid upgrade, so it is vital to check your specific fare class before arriving at the gate.