Each airline makes its own weight restrictions for both carry-on luggage and checked baggage. Some do not restrict carry-on luggage weights but Continental Airlines restricts carry-on luggage to 40 lbs. A checked-baggage weight limit for economy passengers is 50 lbs. per bag. Some airlines provide a higher weight limit for frequent fliers, business and first class travelers or military personnel.
Most airlines weigh baggage at the check-in counter and charge an extra fee for baggage that is over the allowed weight limit. As of October 2010, both Continental and American Airlines charge international economy travelers $50 for each bag weighing between 50 and 70 lbs.
Most airlines have a maximum weight limit for all bags, usually 100 lbs.,at which the luggage is not loaded on the plane, even if extra fees are paid. Check with your airline for its specific weight requirements for international flights. Ensure that all luggage complies with the airline's policy, in terms of size as well as weight.