GC Calculator
POINT to POINT
  Lat Lon
P1
P2
Distance units:
Earth model:

Course 1-2   Course 2-1   Distance
   

Compute true course and distance between points.

Enter lat/lon of points, select distance units and earth model and click "compute". Lat/lons may be entered in DD.DD, DD:MM.MM or DD:MM:SS.SS formats.

Note: If either point is very close to a pole, the course may be inaccurate, because of its extreme sensitivity to position and inevitable rounding error.
POINT from POINT
Lat1
Lon1
Course 1-2
Distance 1-2
Distance units:
Earth model:

Lat2
  
Lon2
 

Compute lat/lon given radial and distance from a known point

Enter lat/lon of initial point, true course and distance. Select distance units and earth model and click "compute". Lat/lons may be entered in DD.DD, DD:MM.MM or DD:MM:SS.SS formats.

Note: The starting point cannot be a pole.
Spheroid of User defined Earth model ^
Major radius a (km):
Inverse flattening 1/f:
(Original script by Ed Williams)