Geodetic calculation methods

Last updated:7 June 2023

Online calculations and downloadable spreadsheets to perform geodetic calculations

Detailed information about the spreadsheets and formulae used in all calculations listed below can be found in the Geocentric Datum of Australia Technical Manual.

Distance calculations

Calculate Great Circle distances using latitude and longitude.

Calculate bearing and distance from latitude and longitude

Use Vincenty's formulae to calculate distance and bearing from latitude and longitude and vice versa.

Convert from geographic to grid coordinates

Use Redfearn's formulae to convert between geographic coordinates (GDA94, latitude and longitude) to grid coordinates (Map Grid of Australia (MGA94), eastings and northings) and vice versa.

Transformation of coordinates

The following are available for download but are not yet available as online calculations.