Calculate direct spherical great-circle flight distances and initial tracks between 40+ premier international hub airports.
How This Calculator Works
Because planet Earth is an oblate spheroid, the shortest distance between any two geographical points is an arc along a Great Circle (an imaginary circle on the globe whose plane passes directly through Earth's center). When plotted on traditional Mercator flat map projections, great circle routes appear curved toward the poles.
For example, a flight from London to Los Angeles does not fly straight across the middle Atlantic; it curves high across Greenland, northern Canada, and Hudson Bay. This route appears longer on flat 2D maps, but is actually hundreds of miles shorter across the curved sphere.
Navigators and flight management systems use the Haversine Formula or Vincenty ellipsoidal formulas to calculate precise spherical distances and initial compass track angles between airports worldwide.
Mathematical Formula
Worked Examples
Example 1: New York (JFK) to London Heathrow (LHR)
Coordinates: JFK (40.64°N, 73.78°W) to LHR (51.47°N, 0.45°W).
Great Circle Distance ≈ 2,999 Nautical Miles (5,554 km / 3,451 statute miles)
Example 2: Los Angeles (LAX) to Tokyo Haneda (HND)
Transpacific curved northern route near the Aleutian Islands.
Great Circle Distance ≈ 4,758 Nautical Miles (8,812 km / 5,475 statute miles)
Frequently Asked Questions
Why do flight paths curve toward the poles on map screens?
Map screens use flat cylindrical or Mercator projections, which stretch areas near the poles. The curved line on the flat map represents a perfectly straight track across the globe.
Do flights always fly the exact great circle path?
Not always. Flight plans deviate around strong headwinds, exploit favorable jet streams, bypass severe thunderstorm clusters, and avoid closed sovereign military airspace.
How many airports are built into this calculator?
This calculator contains accurate GPS coordinates for 40 of the busiest and most iconic international hub airports across all continents.
What is an orthodromic route?
An orthodromic route is the technical mathematical term for a Great Circle route on a sphere.
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