I need coordinates transformation for Point Feature Clases. Situation:

I have imported points in local projected coordinate system. Now I need to get points coordinates in geographic coodinate system. I need to have each point coordinates in attribute table. So, in attribute table I use calculate geometry function. It seems that after I calculate coodinates to geographic system (DMS), seconds parts become incorrect. Is it possible that an error accurs while making a transformation? Does anyone has any other comment on this question?

Coordinates example:

Local system: 6207549.78, 318656.45

WGS system after transformation: 21°5'41,58"E 55°58'4,13"N

Result using different calculator: 21°5'41,64"E 55°58'4,08"N

"Is it possible that an error occurs while making a transformation?" Yes, the positional accuracy of a transformation from one coordinate system to another will result in a positional error. This is the reason why using the correct transformation is important as the correct transformation method will

minimisethe positional error.From my calculation the distance between the two latitude and longitude values is approximately 186 cm.

I think the next question is: Does your data require positions more accurate than that?