Flight distance and time

Measures the great-circle distance, the shortest path over the Earth's surface, between two airports or cities, in kilometres, miles and nautical miles, and draws it on a map.

Estimates the flight time from that distance, and gives the initial compass heading and the time difference between the two ends.

Distance uses the haversine formula on a sphere with the Earth's mean radius, 6,371.0088 km (GRS 80), from the airports' coordinates in OurAirports. A code for a whole city is measured from its main airport's coordinates.

The flight time is the distance at an average 850 km/h, plus 45 minutes for taxiing, take-off, climb, descent and landing, rounded to the nearest five minutes. It is our own simple model, and it is the same for every route.

It is an estimate, never a schedule. Aircraft follow airways and air-traffic routings rather than the great circle, and winds high in the atmosphere change the time: the jet streams generally blow from west to east, so flights with them are quicker than flights against them.

Airlines' timetables also allow for congestion at busy airports and vary by season and aircraft. For real departure and arrival times, ask us for flight options or check with the airline.

It does not know whether any airline flies the route nonstop.