Midpoint Calculator
Click the map to place Point A, then click again to place Point B. The geographic midpoint is calculated instantly.
About This Tool
The Midpoint Calculator finds the geographic midpoint between two points on the Earth's surface. It is used in logistics (finding a fair meeting location), telecommunications (siting a relay between two endpoints), and spatial analysis.
Input
Two points — Point A and Point B — placed on the map or found via search. Clicking a third time moves whichever point is nearer to the new location rather than adding a point, so the calculation always uses exactly two endpoints.
Output
The great-circle midpoint displayed as a distinct marker on the map, with its coordinates in Decimal Degrees and Degrees Minutes Seconds, plus the distance from A to B and from each point to the midpoint.
Key Concepts
- Great-circle midpoint
- The point exactly halfway between A and B along the shortest path over the sphere — equidistant from both. It is computed with spherical (great-circle) geometry rather than a flat average of the latitude and longitude values.
- 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. Great-circle geometry handles both edge cases correctly.
- Spherical model
- The calculation treats the Earth as a sphere, which is accurate to well within a metre for the midpoint of any two everyday points — more than sufficient for planning and analysis.