Coordinate Midpoint Calculator
Find the geographic midpoint (halfway point) along the great-circle path between two latitude/longitude coordinates.
How it works
Bx = cos φ₂·cos Δλ · By = cos φ₂·sin Δλ · φm = atan2( sin φ₁+sin φ₂ , √((cos φ₁+Bx)²+By²) ) · λm = λ₁ + atan2( By , cos φ₁+Bx )
This finds the true midpoint on the great-circle arc, not the naïve average of the two coordinates. Simply averaging latitudes and longitudes fails near the poles or across the ±180° meridian, whereas the vector method here works everywhere on the globe.
Worked example
Between New York and London the midpoint works out to about (52.37, −41.79) — far out in the North Atlantic, which is why the flight path looks curved on a flat map.
Sources: Midpoint — Movable Type Scripts
Frequently asked questions
Why not just average the coordinates?
Averaging latitude and longitude gives a wrong point on curved routes, long distances, or paths crossing the date line. The great-circle midpoint uses 3-D vectors and is always correct.
Is this the same as the centre of a group of places?
No. This is the midpoint of exactly two points. Finding the centre of many locations requires averaging their Cartesian coordinates and re-projecting.
Does longitude wrap correctly?
Yes — the result is normalised into the −180° to +180° range, so routes crossing the antimeridian give a sensible answer.
Related calculators
Educational estimate. Uses a spherical-Earth model; results differ slightly from ellipsoidal (WGS84) calculations.