Flight Distance Calculator
Calculate the great-circle distance between any two airports worldwide. Results in kilometers, miles, and nautical miles.
Frequently Asked Questions
What is a great-circle distance?
A great-circle distance is the shortest distance between two points on the surface of a sphere. On a flat map, the shortest path between two cities appears to be a straight line, but on Earth's curved surface, the shortest path follows an arc. This is why flights between New York and Tokyo fly over the Arctic rather than straight across the Pacific.
Why do airlines use nautical miles?
Aviation uses nautical miles because one nautical mile equals one minute of latitude, making navigation calculations simpler. One nautical mile is approximately 1.852 km or 1.151 statute miles. Airspeed is measured in knots (nautical miles per hour) and flight levels are tied to this system.
Is the calculated distance the same as the actual flight distance?
Not exactly. The great-circle distance represents the theoretical shortest path. Actual flight distances are typically 5-15% longer due to air traffic control routing, restricted airspace avoidance, jet stream optimization, and standard arrival/departure procedures at airports.
How accurate are the airport coordinates?
Airport coordinates in our database are sourced from OurAirports, a public-domain dataset with positions verified against official aeronautical publications. Coordinates use the WGS84 reference system (the same used by GPS) and are accurate to within a few meters for major airports.
Methodology
Distance is calculated using the Haversine formula, which computes the great-circle distance between two points on a sphere using their latitude and longitude coordinates. The formula accounts for Earth's curvature, using a mean radius of 6,371 km. Results are converted to miles (1 km = 0.621371 mi) and nautical miles (1 km = 0.539957 nmi). Note that actual flight distances may be slightly longer due to air traffic control routing, weather deviations, and restricted airspace.