Maidenhead locator converter (ham radio grid square)
Convert GPS coordinates to a Maidenhead locator (also called a "grid square"), the location system used by ham radio operators, and vice versa.
Coordinates → Locator
Locator → Coordinates
What is a Maidenhead locator?
The Maidenhead system (or "grid locator") divides the Earth's surface into a hierarchical grid: a 20° x 10° field (2 letters), subdivided into 2° x 1° squares (2 digits), themselves subdivided into 5' x 2.5' subsquares (2 letters). A 6-character locator like "JN18eu" therefore designates a small rectangular area, not an exact point.
This system is mainly used in ham radio to give your position compactly during radio contacts (QSOs) and contests.
Why doesn't the reverse conversion give exactly the same coordinates?
A locator designates a grid cell, not a precise point. The reverse conversion therefore returns the center of that cell, which may differ slightly from the original coordinates — the more characters the locator has, the smaller the difference.
100% local processing: the conversion runs entirely in your browser via WebAssembly — your coordinates are never sent to a server.