Haversine Distance Calculator

It calculates the great-circle distance between two points on a sphere — the shortest path along the curved surface of the Earth between them, treating the Earth as a perfect sphere with a radius of 6,371 km, which is what people typically mean by "as the crow flies" distance.

Latitude and longitude are angular coordinates on a sphere, not flat x/y coordinates — a degree of longitude represents a much shorter physical distance near the poles than near the equator, so a flat-plane distance formula would give badly wrong results except over very short distances; the Haversine formula correctly accounts for the sphere's curvature.

It's a straight-line distance over the Earth's surface, not a routed distance — actual travel by road, rail, sea, or air will always be longer since those routes have to follow terrain, infrastructure, and legal paths rather than a direct great-circle line.

It's the compass direction (0° = due North, 90° = due East, and so on) you'd need to start heading in from Point A to follow the great-circle path toward Point B — because the Earth is curved, this initial bearing generally isn't the same as the bearing you'd end up needing partway through the journey.

The Earth is actually a very slightly flattened (oblate) spheroid rather than a perfect sphere, so more precise formulas like Vincenty's formula account for that flattening; the difference from Haversine is typically under 0.5%, which is negligible for most everyday distance estimates.