The length of a typical airport runway is 13,123 feet or 4,000 meters at sea level. Airports that are built at higher altitudes have a longer runway depending on the altitude.
For small aircraft weighing less than 200,000 pounds, a minimum runway length of 6,000 feet at sea level is recommended. But for international aircraft that are huge like Airbus A310 and Boeing 777, a runway length of at least 13,000 feet at sea level is recommended.
The runway length is recommended based on factors like aircraft operating weight and type of engine. International aircraft carry much fuel, adding on to the aircraft's weight for takeoff. The world's longest airport runway is 18,045 feet as of October 24, 2014.