I have requirement to convert UTM NAD 1927 Northing (4804172), Esting(753352) to Geographic coordinatesystem(Degrees Minutes, Seconds).

Iam doing like below

m_mapPoint[0] = new esri.geometry.Point(4804172, 753352, new esri.SpatialReference({ wkid: 26712 })); var geogPt = esri.geometry.webMercatorToGeographic(m_mapPoint[0]); gsvc.project([geogPt], outSRgc83, convrtCord83);

when I project the point I am getting result as NaN. But It's equivalent DMS should be 42 21' 58.42'', 107 52' 29.28'' and map point should be 42.5698, -107.5229

Please help me how to resolve it.

Thanks, Uday

  • NaN means Not a Number so I guess you have error somewhere in your statement. Try debug your middle results and see what is causing the error.
    – Krystian
    Feb 26, 2013 at 14:26
  • 1
    Try switching the northing, easting in the point to easting, northing order. There should also be a transformation but let's get rid of the NaN first.
    – mkennedy
    Feb 26, 2013 at 17:39
  • It is working perfectly. Thankyou verymuch. Thanks, Uday
    – user14628
    Feb 27, 2013 at 11:52
  • Please don't add "thank you" as an answer. Instead, vote up the answers that you find helpful.
    – Zachary
    Feb 27, 2013 at 13:37

1 Answer 1


The webMercatorToGeographic function is a shortcut way to convert wkid 102100 (web mercator) to wkid 4326 (lat long). You'll need to use a GeometryService to reproject your point, since you're using a different spatial reference.

m_mapPoint[0] = new esri.geometry.Point(4804172, 753352, new esri.SpatialReference({ wkid: 26712 }));
var params = new esri.tasks.ProjectParameters();
// add array of points
params.geometries = m_mapPoint; 
// Output Spatial Reference in lat/long (wkid 4326)
params.outSR = new esri.SpatialReference({wkid: 4326});
// run callback once the geometry service returns the reprojected results.
gsvc.project(params, callback, errback);
  • 1
    +1 for this. Don't use webMercatorToGeographic if your source is in NAD27. At that lat/long, your coordinates will be shifted by ~50 meters at the least.
    – Mintx
    Feb 27, 2013 at 17:13

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