20-mile Hex Map
20-mile hexes are the standard size for mapping expansive areas of the game world, called sheet maps. Hexes measure 20 miles from side to side, with an area of 259 square miles per hex.
Area references for national districts are measured in hexes rather than square miles, as it is easier for players to envision an area that covers seven 20-mile hexes than 1,813 square miles. Incidentally, seven 20-mile hexes would be an area slightly larger than the U.S. state of Rhode Island.
The names for these smaller hexes are a misnomer, because a 6-mile hex is 6.67 miles across, while a 2-mile hex is 2.22 miles ... but simplifying the names makes it easier to refer to maps of these sizes. The accurate sizes for all map scales are carefully noted for actual mapping purposes.
See Map Scales