Bearing Calculator

About this calculator

The initial compass bearing between two points on the globe follows a great-circle path, not a straight line on a flat map, so it is computed with spherical trigonometry rather than simple plane geometry: θ = atan2(sin Δλ·cos φ2, cos φ1·sin φ2 − sin φ1·cos φ2·cos Δλ), where φ1, φ2 are the latitudes and Δλ is the difference in longitude, with the result normalized to 0–360° and read clockwise from true north.

Because a great-circle route's bearing actually changes continuously along the path (except for meridians and the equator), this “initial bearing” is only the heading at the starting point — the value that ships and aircraft plotting a course, and hikers or surveyors doing basic geodesy, actually read off a compass at departure.