Coordinate Conversion

All coordinates refer to a specific datum or projection. Before two coordinates can be compared they need to be in terms of the same system. The process to change coordinates between datums and projections is called either a conversion or a transformation.

Transforming coordinates is a multi-step process as described in the diagram below. Projection coordinates (metres North and East) must first be converted to datum coordinates (latitude and longitude) and then transformed back to the target datum and/or projection.

Additional information and examples of each transformation step is provided in the pages described below.

Online conversions

Tools and instructions for automated online conversion of coordinates and heights between different datums and projections. more...

Geodetic datum conversions

Overview, formulae and examples for converting coordinates between NZGD2000, NZGD1949, WGS84 and CIGD1979 datums. more...

Projection conversions

Overview, formulae and examples for converting Transverse Mercator, Lambert Conformal and NZMG projection coordinates to and from their respective geodetic datums. more...

Height conversions

Overview, formulae and examples for converting between ellipsoidal (GPS, NZGD2000), normal orthometric (MSL) and geoid heights. more...