About Grid Squares and Headings
A grid square (Maidenhead locator) is a short code for a location. The first four characters, like FN31, mark an area roughly 100 by 70 miles in the US; six characters, like FN31pr, narrow it to a few miles. FT8 and most contests exchange the four-character version.
The heading is the direction to point a beam antenna, measured clockwise from true north (not magnetic north). It follows the great circle, the shortest route over the globe, which is why the heading to Europe from the US is northeast rather than east. The long path goes the other way around the world; sometimes it is the one that is open.
A four-character grid is treated as its center point, so distances between nearby four-character grids are approximate.
Look up a callsign’s grid → · Grid square in the Dictionary →