The time required for an airport transfer depends on whether you are navigating a layover or traveling from a city center. For connecting flights, it is generally recommended to allow at least 2 hours for domestic transfers and 3 to 4 hours for international connections, especially in the U.S. where you may need to clear customs and re-check bags. If you are traveling from a city to the airport, a good rule of thumb is to aim to arrive at the terminal 2 hours before domestic departures and 3 hours before international flights. You must then add the actual transit time, which can vary wildly: for example, a train might take 30 minutes, while a taxi in heavy traffic could take 90 minutes. In 2026, with increased security protocols and biometric processing, arriving early is more critical than ever; always check local traffic apps or rail schedules and add a 30-minute "buffer" for unexpected delays like road construction or long security lines.