best way to convert a csv file with UTM to lat long

[MarinaMeter]

I have a huge amount of .csv files each with hundreds of rows and each has its own value of an easting and northing

How can i quickly change these UTM coordinates and convert them to a lat/long  coordinate value using ArcMap.

What might you suggest is the most efficient method? Im very new to this, so any help and details is greatly apprecaited

[PROBERT68]

Thank you. Good luck on what your decision are...AND let us know what you have accomplish on this...

[MarinaMeter]

im actually having a heck of a time, let me explain:

I was given an x value of (2514960.36447139) an a Y value of (2042479.38586146), Ok now when I set my layer properties to NAd83 Utm Zone 11,  i then convert csv to events, i then convert to a shape file with the layers data frame, I now end up somewhere in mexico, this is the first issue.

[PROBERT68]

It sounds like you got it right but you need to add the x and y columns and make them to longitude and latitude before you can convert to shapefile.

[DarrenWiens2]

Does it appear in the correct place when you make your event layer?

[MarinaMeter]

No it doesnt here is what I was given it is not in mexico for sure

[DarrenWiens2]

Then I guess your coordinates aren't in UTM Zone 11. Even if you switched the coordinates, it's still in Mexico.

[MarinaMeter]

hmmm, i need to convert these to lat/long  it should be in canada above idaho.............eeeek

[DarrenWiens2]

You can rule out these usual suspects:

BC Albers

Canada Albers

Canada Lambert

Alberta 10TM

Did you perhaps get these coordinates from a survey company, who like to confuse people by using a custom coordinate reference system?

[MarinaMeter]

no, supposedly they were converted from x,y coordinates to a NAD83 projection, then folks tinkered with them and exported them back to the values above, now they want it back on lat and long coords. I really have a great passion for GIS but this is making me nuts!!

when i put it i this handy dandy excel converter this is what i get

[DarrenWiens2]

And, those lat/longs are in Mexico.

I would revisit this part, "then folks tinkered with them". The coordinates you have now are just not correct (at least, not for UTM Zone 11).