This page outlines multiple ways to transform geodetic coordinates. The choice of which method is the most appropriate will depend on the accuracy of the coordinates being converted and their intended use.

There are three ways to transform NZGD1949 geodetic coordinates (latitude and longitude) to NZGD2000. Each of the transformation methods has different accuracy limits.

Transformation MethodNominal Accuracy
3 parameter similarity5 metres
7 parameter similarity4 metres
Distortion grid0.1 - 1.0 metres

These transformations are formally defined in the LINZ standard LINZS25000 (Standard for New Zealand Geodetic Datum 2000), and are summarised in the associated NZGD2000 fact sheet (LINZG25700).

Because NZGD1949 is only defined as a horizontal datum all of the transformations described above can only be applied to horizontal coordinates. Heights cannot be transformed in terms of NZGD1949.

Three & seven similarity transformations (NZGD1949 to NZGD2000)

Overview and details of the three and seven parameter similarity transformations for converting between NZGD1949 and NZGD2000. more...

NZGD1949 - NZGD2000 distortion grid

Overview and details of the distortion grid for converting between NZGD1949 and NZGD2000. more...