For example, for flights from Sydney (SYD) to London Heathrow (LHR), then to Los Angeles (LAX) and, finally, back to Sydney (SYD), using :
Code:
Distance
From Lat1 Lon1 To Lat2 Lon2 (mi) (km)
SYD -33.94610 151.17700 LHR 51.47060 -0.46194 10570 17011
LHR 51.47060 -0.46194 LAX 33.94250 -118.40800 5440 8755
LAX 33.94250 -118.40800 SYD -33.94610 151.17700 7490 12054
with 3956.559mi & 6367.465km for the earth's (average) radius.
For a practical implementation see:
https://www.msofficeforums.com/excel...using-lat.html