Use this web application to calculate the great-circle distance (km) between the centers of grid squares.


  • To calculate distances relative to a reference grid, enter the reference grid as either a 4-character or 6-character grid square. Enter/paste a list of 4- or 6-character grids (separated by spaces, commas, tabs, etc) into the text area.
  • To calculate distances between grid pairs, enter/paste a list of 4- or 6-character grid square pairs into the text area. Each pair must be separated by a space, comma, tab, etc. with one pair per line.

Measurement units:miles   kilometers   points (ARRL: km, always round up)   points (km, truncated)   points (km, round off)

Distance from reference grid   Distance between grid pairs

Reference Grid

List grid squares below: