hope this helps (check attached link and picture):

https://stackoverflow.com/questions/1185408/converting-from-longitude-latitude-to-cartesian-coordinates

kindly refer the attached link....

https://www.datanumen.com/blogs/convert-utm-coordinates-latitude-longitude-values-via-excel-vba/

Good reference cited by respected Aows Neeamy and Kirubakaran Muniraj.  An link is attached. which automatically converts your meters value into lat long. Hope it will work for you. 

https://www.uwgb.edu/dutchs/UsefulData/ConvertUTMNoOZ.HTM

Thank you so much . i shall go through all of them

Use software geographix. Understand the reference ellipsoid like Everest, WGS 1972, WGS 1984. As a thumb rule 1degree is 111km

Dear Amobichukwu Amanambu,

Your question can be either answered easily (see the contributions above) if you know in which coordinate system these coordinates are. If not, there could be only guessed what your coordinates mean. Assuming that you are using UTM, you still need to know which zone is used in your case. (See the link provided by Raju above.)

Since your coordinates seem to have meter precision, it is INEVITABLE to know the geodetic datum, and the projection that have been used in this system. Anything else will corrupt your meter precision after conversion.

There are many software that are able to convert coordinates in hundreds of coordinate systems. Quantum GIS is a free one. A Swiss army knife of commercial software of that kind is Global Mapper.

Kind regards,

Balázs

Thank you so much Balaze Szekely and all others for the info. very deep!

You have your coordinates on a map projection in meters  (so you know the datum and map projection in which they are), so you just need to move back only on the datum and have the transformation, so as to go from meters (E, N), to degrees (latitude and longitude).

Hope this helps!