The amount of time required for a flight transfer, known as the Minimum Connection Time (MCT), depends heavily on the airport layout and whether you are changing from a domestic to an international flight. For a standard domestic-to-domestic connection at a medium-sized airport, 60 minutes is generally sufficient. However, for international transfers involving customs, immigration, and terminal changes (like at JFK or Heathrow), you should allow at least 2 to 3 hours. If you are booking separate tickets on different airlines, you should extend this to 4+ hours to account for potential delays, as the second airline is not obligated to rebook you if you miss the flight.