The unit of matrices and algorithms that the program uses for calculation is independent of the unit you choose for input. The ideCAD program allows you to work with any metric or imperial unit you want. You can specify the input units in the settings tab in the program. Options: Length unit, Force unit, Rebar diameter unit, unit used in sections, Mass unit, Deformation unit and angle unit can be selected Length Unit Selection: Force Unit Selection: Rebar Diameter Unit Selection: Section Unit Selection: Mass Unit Selection: Deformation Unit Selection: Angle Unit Selection: