🧭 Great-Circle Distance Calculator
Enter the latitude and longitude of two points to get the great-circle distance between them in nautical miles, kilometres, and statute miles — the shortest track over the globe.
🛫 How Far Is the Flight?
What is a Great-Circle Distance Calculator?
It measures the shortest distance between two points on the Earth using the Haversine formula, treating the planet as a sphere. Feed it the coordinates of a departure and a destination and it returns the great-circle distance — the ideal track an aircraft would fly if airways, weather, and ATC never got in the way.
Pilots, dispatchers, and frequent flyers use it to size up a route, compare two airports, estimate fuel and flight time, or settle how far apart two cities really are. The figures are estimates for planning — the routed distance you actually fly is longer, so verify against a current flight plan and charts.
❓ Frequently Asked Questions
What is a great-circle distance?
A great circle is the largest circle you can draw on a sphere, and the arc of it between two points is the shortest path over the Earth's surface. For flights that means the most direct track over the ground — which on a flat map looks like a curve bending toward the poles. Enter each point's latitude and longitude and the calculator returns that distance in nautical miles, kilometres, and statute miles.
Why do pilots use nautical miles instead of statute miles?
One nautical mile equals one minute of latitude, so it maps directly onto navigation charts and lines of position — a degree of latitude is a tidy 60 nautical miles. That link to the Earth's geometry is why aviation and marine navigation use nautical miles and knots (nautical miles per hour). The tool shows all three units so you can cross-check against whichever your chart or plan uses.
Is the great-circle distance the same as the distance I'll actually fly?
No — it's the theoretical minimum. Real flights follow published airways and waypoints, take ATC vectors and reroutes around weather or restricted airspace, and rarely track the perfect great circle, so the flown distance is longer. Use this figure for planning and comparison, then verify the routed distance on a current flight plan.
Where do I get the latitude and longitude of an airport?
Airport coordinates are published in the official aeronautical information publication (AIP) and airport directories, and most flight-planning apps list them by ICAO/IATA code. Enter them in decimal degrees, with south latitudes and west longitudes as negative numbers. Small errors in coordinates only slightly change the distance, so approximate positions still give a useful estimate.