Instructions for online height conversions

How to transform heights between vertical datums.

  1. Open the vertical datum conversion page
  2. Choose the input height coordinate system.
    • If "ellipsoidal" is selected, the input height must be an ellipsoidal height in terms of the input coordinate system selected in (2).
    • If New Zealand Vertical Datum 2016 or one of the thirteen mean sea level datums is selected, the input height must be in terms of that datum.
    • If "none" is selected, no height transformation is done, unless the output Height Option is "NZGeoid2016 geoid height".
  3. Choose the output Height coordinate system.
    • If "ellipsoidal" is selected, the output height will be an ellipsoidal height in terms of the output coordinate system selected in (5).
    • If New Zealand Vertical Datum 2016 or one of the 13 mean sea level datums is selected, the output height will be in terms of the chosen datum.
    • If the conversion is between two mean sea level datums, the datums should not be widely separated (eg Auckland and Bluff).
    • If "NZGeoid2016 geoid height" is selected, the height of NZGeoid2016 above the ellipsoid at the point is calculated.
  4. Choose the input coordinate system - this is a New Zealand coordinate system in which the location of the points to convert is defined
  5. Choose the coordinate format.  This has options for whether the points being converted have an identifying name or not, the order of the east and north (or longitude and latitude) coordinates, and the character used to separate the coordinates.
  6. Click the "Enter coordinates" button.
  7. Enter the coordinates in the appropriate format as shown by the example coordinate and click "Convert coordinates".