Midpoint Calculator

About This Tool

The Midpoint Calculator finds the geographic center of two or more points on the Earth's surface. It is used in logistics (finding the optimal meeting location), telecommunications (siting a relay between two endpoints), and spatial analysis.

Input

Two or more points placed on the map or found via search. Each additional point shifts the midpoint toward it — the result is the equal-weight geographic centroid of all inputs.

Output

The geographic midpoint displayed as a distinct marker on the map, with its coordinates in Decimal Degrees and Degrees Minutes Seconds.

Key Concepts

Geographic midpoint

The point on the Earth's surface that minimises the sum of great-circle distances to all input points (for two points, it is exactly equidistant from both). It is computed by converting each lat/lng to 3D Cartesian coordinates on the unit sphere, averaging the x, y, z components, and projecting the mean vector back to lat/lng via atan2.

Why not average coordinates directly?

Averaging lat/lng values as plain numbers fails in two cases: (1) near the antimeridian (±180° longitude), where the mean of 170° E and 170° W would incorrectly compute as 0° rather than the correct 180°; (2) near the poles, where longitude becomes geometrically meaningless. The 3D Cartesian method handles both edge cases correctly.

Centroid vs. midpoint

For exactly two points the result is the midpoint — the unique point halfway between them along the great circle. For three or more points the result is the geographic centroid, which is not equidistant from all inputs but rather the equal-weight average of their 3D positions.