Weighing. If you have both checked and carry on luggage, usually both are going to be weighed at the check-in/luggage drop. If you only have a carry on and check-in online you have small chances to have your luggage weighed, however it might not be true if you apparently struggle with it.

In 2026, airlines are increasingly weighing carry-on backpacks, particularly in the budget and international sectors. While major U.S. legacy carriers like Delta or United rarely weigh backpacks unless they look visibly overstuffed, low-cost carriers (ULCCs) and many international airlines (especially in Europe, Asia, and Australia) strictly enforce weight limits, often set at 7 kg (15 lbs) or 10 kg (22 lbs). Gate agents frequently use portable scales or require passengers to place their bags on a scale during check-in or boarding. If your backpack exceeds the limit, you may be forced to gate-check the bag and pay a significant fee, which can reach $75 or more in 2026. To avoid this, travelers are encouraged to use lightweight "travel-specific" backpacks and wear their heaviest clothing items through security. Always check the "Contract of Carriage" for your specific airline, as the "if it fits, it sits" era is rapidly being replaced by rigorous weight-based enforcement to maximize fuel efficiency and cabin safety.