In ArcMap 10.2, I have .asc files that contains a map of a predicted species distribution I got from using MaxEnt. When I import the file with the data frame properties set to North American Albers Equal Area the map shows up only about 60 meters across and 50 meters tall, when the coordinates are originally from Top: 76.06, Left: -163, Right: -102.16, Bottom: 27.10 - it even says these coordinates in the Extent information in the Layer Properties.

I converted the .asc to raster, reclassified the values (0 for absent, 1 for present), extracted the present values using the Extract by Attribute tool, then turned the present area into a polygon, all while changing the layers projections-yet still it remains small. The ultimate reason for making the projection correct is to calculate the predicted area of the species. The area calculated in the attribute table is also incorrect.

What could possibly be happening?

  • 1
    Your grid is lat/lond based, I.e. degrees. Define it's projection, it will expand
    – FelixIP
    Apr 16, 2016 at 7:40

2 Answers 2


To expand on @FelixIP's comment: the coordinates seem to be wgs84 coordinates, that is if you set them as wgs84 with epsg 4326 then they will show up probably correct.


Problem solved using SDMToolbox for ArcMap. I used all of the tools in this toolbox to convert the map as I described in the steps above and the projection came out with the proper area!

Defining the projections did nothing before using the toolbox.

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