In the “Help” file, look up “projection” and then see “saving data to a new coordinate
system.”
Exporting data to a new coordinate
system
Related topics
About saving data to a new projection
When you export data from ArcMap, you can choose to create a new feature class using
a different coordinate system than that of the source data, use the coordinate system of
the data frame, or use the coordinate system of the feature dataset to which you are
exporting the data.
In ArcCatalog, when you export data to a feature dataset in a geodatabase, it will use the
coordinate system of the feature dataset. If you export data as a standalone feature class
or to a file-based data source, it will have the same coordinate system as the source data.
The ArcToolbox Project tool allows you to make a copy of your data and change its
coordinate system. This tool changes the coordinate system of the data and transforms the
shapes in the data to use the new coordinate system. You can use the Project tool as part
of a model or as you need it while working in ArcMap or ArcCatalog.
If your data's geographic coordinate system uses a different datum than that of the new
feature class, you will likely write spatially inaccurate data. Instead of directly writing to
the new feature class, make a copy of the original feature class and use the Project tool to
reproject that feature class to the coordinate system that you ultimately want to use. As
part of using the Project tool, you will be able to specify a datum transformation. Once
you have projected the copy, you can copy it into the new workspace and delete the first
copy. This applies to any place in ArcMap or a geoprocessing tool that is able to write
new data.
Learn more about exporting data to shapefiles or feature classes
How to save data in a new projection
Exporting features to a shapefile that uses the data frame's coordinate
system
Exporting features to a feature dataset in a geodatabase