Airport capacity is a multi-dimensional metric primarily measured by throughput over a specific time period, usually one hour. The most common metric is the Aerodrome Arrival Rate (AAR), which specifies the number of aircraft that can safely land on a specific runway configuration under current meteorological conditions (VMC vs. IMC). Beyond the runways, capacity is also measured at the terminal level, looking at "Typical Peak-Hour Passenger" (TPHP) flow, which assesses how many people can pass through security, check-in, and gates without excessive delays. Other factors include "Gate Capacity" (how many aircraft can be parked and serviced at once) and "Airspace Capacity" (the density of the surrounding flight corridors). In 2026, many airports use sophisticated AI modeling to calculate "Operational Capacity," which adjusts the theoretical maximum for real-time variables like wind direction, taxiway construction, and ground crew availability. Balancing these different "choke points" is essential for airport planners to prevent "saturation," where demand exceeds the system's ability to process flights, leading to the "domino effect" of delays seen during peak travel seasons.