Working with Units in Files That Will Be Saved to DWG

When saving a DGN file to DWG, the linear units in the resulting DWG file depend on a combination of:

the Working Units, Master Units, Sub Units, and Accuracy settings in the Design File Settings dialog
the Units setting on the Save As DWG/DXF Options dialog

The table shows combinations of settings in the DGN file, and the resulting linear units when the file is saved to DWG and opened in AutoCAD.

Master Units	Sub Units	Accuracy	Units in Save As DWG/DXF Options	Resulting Units in AutoCAD
Feet	Inches	Decimal	Master Units	Decimal/Engineering When using MU for the Format (Design File Settings dialog), if configuration variable MS_DWG_FEETUNIT_AS_ARCHENG is set, the resulting units are Engineering. If not set, the resulting units are Decimal.
Feet	Inches	Decimal	Sub Units	Engineering
Feet	Inches	Decimal	Inches	Engineering
Feet	Inches	Decimal	Feet	Decimal
Feet	Inches	Decimal	Any other	Decimal

Feet	Inches	Fractional	Master Units	Architectural/Fractional When using MU for the Format (Design File Settings dialog), if configuration variable MS_DWG_FEETUNIT_AS_ARCHENG is set, the resulting units are Architectural. If not set, the resulting units are Fractional.
Feet	Inches	Fractional	Sub Units	Architectural
Feet	Inches	Fractional	Inches	Architectural
Feet	Inches	Fractional	Feet	Fractional
Feet	Inches	Fractional	Any other	Fractional

Feet	Any other	Decimal	Inches	Engineering
Feet	Any other	Decimal	Any other	Decimal
Feet	Any other	Fractional	Inches	Architectural
Feet	Any other	Fractional	Any other	Fractional

Inches	Any Sub Unit	Decimal	Master Units	Engineering
Inches	Inches	Decimal	Sub Units	Engineering
Inches	Any except Inches	Decimal	Sub Units	Decimal
Inches	Any Sub Unit	Decimal	Inches	Engineering
Inches	Any Sub Unit	Decimal	Feet	Decimal
Inches	Any Sub Unit	Decimal	Any other	Decimal

Inches	Any Sub Unit	Fractional	Master Units	Architectural
Inches	Inches	Fractional	Sub Units	Architectural
Inches	Any except Inches	Fractional	Sub Units	Fractional
Inches	Any Sub Unit	Fractional	Inches	Architectural
Inches	Any Sub Unit	Fractional	Feet	Fractional
Inches	Any Sub Unit	Fractional	Any other	Fractional

Any Master Unit	Any Sub Unit	Decimal	Inches	Engineering
Any Master Unit	Any Sub Unit	Decimal	Any other	Decimal
Any Master Unit	Any Sub Unit	Fractional	Inches	Architectural
Any Master Unit	Any Sub Unit	Fractional	Any other	Fractional