Distance between airports in seconds
Type the airports in the order you will fly them, two to four ICAO codes, and choose Calculate. The result gives the total distance in nautical miles, statute miles and kilometers, and each leg's distance with its true course out and in. Add a ground speed to see the time en route, and a fuel burn in gallons per hour to see the fuel. Change the speed or the burn and the result updates without another lookup.
The calculator opens on New York JFK to Los Angeles: 2,150.6 nautical miles, 2,475 statute miles or 3,983 km, leaving on a true course of 274° and arriving on 246°. At a ground speed of 450 knots that is 4 hours 47 minutes.
Why the course changes on the way
The shortest path between two points on the Earth's surface is a great circle, or more exactly a geodesic on the Earth's ellipsoid. Except along a meridian or the equator, its true course changes all the way: JFK to LAX leaves heading 274° and arrives heading 246°, because the great circle bends north of the straight line you would draw on most flat maps. That is why the table gives two courses for each leg.
For a short VFR leg the change is small, and the course you measure on a sectional chart for the VFR nav log is close to the course out. On long legs, flight planning splits the route into shorter segments, each with its own course. True courses here are relative to true north; convert to magnetic with the variation printed on your chart, then apply the wind with the wind correction angle calculator.
Nautical miles, statute miles and kilometers
Aviation measures distance in nautical miles: one nautical mile is exactly 1,852 meters, about 1.1508 statute miles. A statute mile is exactly 1,609.344 meters. The nautical miles to km converter converts any distance between the units, and the time, speed and distance calculator solves for any one of the three from the other two.
How the distance is calculated
The calculator works on the WGS-84 ellipsoid, the Earth model GPS uses, with Vincenty's inverse formula, which gives the distance and both courses between two points on an ellipsoid. It is tested against the classic example from Vincenty's paper, the line from Flinders Peak to Buninyong in Victoria, Australia: it reproduces the published 54,972.271 meters and both courses to the hundredth of a second.
Many online calculators treat the Earth as a sphere, which is simpler and differs by a few tenths of a percent: on a sphere of the mean Earth radius, JFK to LAX comes out at 2,145.9 nautical miles, 0.2% shorter. For two points almost exactly opposite each other on the globe, the ellipsoid formula can fail to settle; the calculator then uses the sphere and says so.
Airport positions come from the Aviation Weather Center's airport data at aviationweather.gov, given to four decimal places of latitude and longitude, about 11 meters. Only the airport codes you type go to the airport service; the distance and courses are worked out in your browser.
Time and fuel
Time en route is distance divided by ground speed, and fuel is time multiplied by the burn per hour. Both come from the planning numbers you enter, so they are only as good as the ground speed and burn rate you use: the calculator adds no taxi, climb or reserve fuel. Work out the reserve your flight needs, and for a cross-country flight build a full nav log with checkpoints, winds and fuel for each leg.
Sources
- T. Vincenty, "Direct and inverse solutions of geodesics on the ellipsoid with application of nested equations", Survey Review 23 (176), 88–93, 1975: the inverse formula and the Flinders Peak to Buninyong test line.
- WGS-84 ellipsoid: semi-major axis 6,378,137 m, flattening 1/298.257223563 (U.S. National Geospatial-Intelligence Agency).
- Aviation Weather Center, Data API airport data (aviationweather.gov), read October 11, 2026: airport positions, including the JFK and LAX example.
Questions pilots ask
How do I find the distance between two airports?
Enter both airports' ICAO codes, such as KJFK KLAX, and choose Calculate. The calculator looks up each airport's position and gives the shortest distance over the Earth's surface in nautical miles, statute miles and kilometers, with the true course leaving and arriving. JFK to LAX is 2,150.6 nautical miles.
Is the flight distance the same as the distance flown?
No. The great-circle distance is the shortest possible path. Real flights are longer: departure and arrival procedures, airways, air traffic control routing and detours around weather all add miles, and the wind changes the time, not the distance.
Why does another calculator give a slightly different distance?
Usually because of the Earth model or the airport positions. This calculator measures on the WGS-84 ellipsoid, the model GPS uses; a formula that treats the Earth as a sphere differs by a few tenths of a percent, 4.7 nautical miles on JFK to LAX. Airport positions can also differ slightly between sources.
Can I use three-letter airport codes?
For airports in the contiguous United States, yes: JFK is looked up as KJFK. Elsewhere the three-letter code is an airline code, not the ICAO code, so enter the four letters: London Heathrow is EGLL, Toronto Pearson CYYZ.
How is the time en route worked out?
Distance divided by ground speed. Use your ground speed, not your true airspeed: the wind triangle in the wind correction angle calculator turns true airspeed and the forecast wind into ground speed. Add a fuel burn per hour and the calculator multiplies it by the time.