Units and Coordinates for DWG/DXF Exports

Use the Units tab of the Modify DWG/DXF Export Setup dialog to specify DWG units to use when exporting the Revit project.
Note: When modifying an export setup, Revit LT does not allow you to specify the basis for the coordinate system.

One DWG unit is

Select the appropriate unit.

For imperial projects, the default unit is inches. For metric projects, the default unit is millimeter. This sets the default unit for the exported DWG/DXF file.