Instructions for carrying out online height conversions

How to use the detailed online coordinate conversion utility to transform heights between vertical datums.

  1. Choose detailed online coordinate conversion.
  2. Choose the input coordinate system. For height transformations, this chooses the coordinate system for the horizontal coordinates which must be included for each point.
  3. Choose the input coordinate order and coordinate format.
  4. 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".
  5. Choose the output coordinate system. For height transformations, this chooses the output coordinate system for the horizontal coordinates. This should be the same as the input coordinate system.
  6. Choose the output coordinate order and coordinate format.
  7. 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.
  8. Choose the coordinate precision. This does not affect the precision of the transformation, only the precision of the output coordinates. In making this selection, it is important to consider the accuracy of the NZGeoid2016 model, the datum offsets, and the input heights.
  9. Click the "Enter coordinates" button.
  10. Enter the coordinates in the appropriate format and click "Convert coordinates".
Last Updated: 24 June 2016