The conversion of coordinates from New Zealand Map Grid (NZMG) to New Zealand Transverse Mercator 2000 (NZTM2000) is a three-stage process:

  1. De-project NZMG coordinates to NZGD1949 geographic
  2. Convert NZGD1949 geographic coordinates to NZGD2000
  3. Project NZGD2000 geographic coordinates onto NZTM2000

A single set of equations to directly transform coordinates between projections is not available.

This conversion process is automated on the online conversion utility and in downloadable software.