🌍 Great Circle Distance & Course
Distance and true courses between two points
About this calculator
The shortest path between two points on Earth is a great circle arc, not a straight line on a flat map. This calculator uses the haversine formula to find that distance in nautical miles, plus the initial and final true courses, which differ because the route constantly curves. Over long distances the savings versus a constant-heading rhumb line are significant.
Tip: for short hops the difference is negligible, but on a transatlantic leg the great circle can save hundreds of miles. That is why airliners fly curved tracks.