Convert the coordinate system of a grid file using Surfer

There are times when you may need to change the coordinate system of the grid file itself, instead of just a map, for use in Surfer. This may be the case when performing grid operations such as Grid Calculus or when working with 3D surface maps.

The Grid Calculus commands require the same X, Y, and Z units in order to provide meaningful results.  For example, a grid file with Z values in feet and XY coordinates in Lat/Lon will result in a very small volume with the units lat degrees * long degrees * feet. Similarly, slope analysis of Lat/Lon can result in all slopes being near 90°. 

3D surface maps do not support coordinate systems and therefore require the same coordinate system for all grids and files used to create each map layer. 

To convert a grid to a new coordinate system in Surfer, follow the steps below.
  1. Click Grids | Edit | Project.
  2. In the Grid Project dialog, click Browse, select your grid file, and click Open.
  3. Click Set in the Input Grid section.
  4. In the Assign Coordinate System dialog, select the coordinate system of the original data and click OK.
  5. Click Set in the Output Grid section.
  6. In the Assign Coordinate System dialog, select the coordinate system you want the grid converted to and click OK.
  7. Click OK in the Grid Project dialog to create the new grid file.


Updated November, 2021


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Date Votes
  • Grids | Edit | Project.

    Is this feature built into automation?

    I want to convert coordinates without changing the grid.

  • This command is not yet built into automation, but I have added your vote to our suggestion file for this feature to be added. Should we add it to future versions we will let you know!


    Thank you for your feedback, we greatly appreciate it! 




    Golden Software

  • Hello Surfer,

    I tried following the instructions above but my grid is not changed to UTM values. Axes are still labelled with decimal degrees values. Kindly help.

  • Hi Kefa,

    If your Map coordinate system is still set to lat/long, then the map axes will display in degrees regardless of the projection of the grid file. You can modify the projection in the map by following the steps in this short video: Surfer Coordinate Systems Training Video. If you're still having difficulty after watching the video, please send an email to with your SRF project attached and we can help you out.



    Golden Software


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