Airlines have recently updated their carry-on baggage policies, with changes impacting both domestic and international travelers. Virgin Australia adjusted its domestic rules in February 2026, limiting economy passengers to one standard-sized bag weighing up to 8kg, plus a smaller personal item that must fit under the seat. Similarly, international carriers like Air Canada have introduced stricter rules, allowing only one personal item for basic fare passengers on flights across North and Central America. These changes reflect a trend among airlines to refine baggage allowances to manage costs and improve operational efficiency. Carry-on baggage rules vary significantly between airlines, even when operating the same type of aircraft. For instance, a flight from Sydney to Melbourne on a Boeing 737 might have different weight and size restrictions depending on the airline and the type of ticket purchased. Qantas allows one small personal item and one standard bag of up to 10kg, or two smaller bags totaling 14kg. In contrast, the budget carrier Jetstar offers a combined allowance of 7kg across two items, highlighting the diversity in policies among different carriers. Airlines must consider the total weight of an aircraft, which includes the plane itself, fuel, supplies, cargo, passengers, and baggage. While checked baggage is measured at check-in, carry-on bags are often estimated based on average passenger weights. In Australia, the standard adult passenger weight was 77kg in 1998, but it has since been updated to 81.8kg for men and 66.7kg for women on planes with 150-299 seats. Airlines can request approval from the Civil Aviation Safety Authority to set their own weight and baggage standards, allowing for more tailored policies. The growth of low-cost airlines has led to more diverse baggage rules, as carriers increasingly rely on ancillary revenue—money earned from extra services like additional luggage, in-flight WiFi, and meals. According to the International Air Transport Association, revenue from such services, including extra baggage fees, is expected to reach $144 billion this year. This financial strategy has pushed airlines to be more flexible with their baggage policies, often offering different options depending on the ticket class or fare type. Carry-on baggage can also pose challenges during boarding and in emergencies. Heavier bags can slow down the boarding process, and retrieving them during an evacuation can delay critical safety procedures. To mitigate these issues, airlines encourage passengers to pack lighter and adhere to baggage limits. This not only helps ensure timely departures but also contributes to a safer and more efficient travel experience.