How to Measure Luggage Correctly for Air Travel In addition to that, we also explain other things, such as do you include wheels in the measurements, what’s linear inches, cover the fees for oversized luggage, and more. In this article, we explain the correct way of measuring luggage for air travel. Party, it’s because of the increased airline security but mostly it’s because the competition between airlines is only increasing, and they compensate that with extra fees for oversized luggage. Today, airlines are getting stricter and stricter on airline restrictions.