Enter your trip and GateCast checks it against a year of real flight records: US DOT data for US trips and ANAC data for trips in Brazil.
Flights and times come from the airport's schedule where it covers your date, and otherwise from last year's schedules. Check the airline for the current timetable.
Some international flights aren't graded yet.
Use the date your first flight departs.
Connecting at Atlanta (ATL), the world's busiest airport? Once you're through security, every concourse connects behind it, linked by the Plane Train.
Changing planes at Austin (AUS)? Every airline now uses one terminal and all four security checkpoints lead to all gates. Older advice about a separate South Terminal is out of date.
Connecting at Nashville (BNA)? Most gates are a walk apart, but gates C4–C11 are a bus ride across the apron. How to plan it, from a pilot.