# What is the meaning of the unit [mrad] for a rotation?

For the unit of the rotation angle, there is an [rad] in RSTAB.

The results of the node deformation in Table 3.6, for example, are given in milli-radians [mrad].

The following general formulas apply for the conversion of the angular dimensions, whereby [rad] must be used for the unit of the arc length dimension:

From arc length dimension to degrees: alpha = (180° / pi) * x

From degrees to arc length dimension: x = (pi / 180 °) * alpha

The following formula applies for the direct conversion with the [mrad] unit used in RSTAB:

From arc length dimension to degrees: alpha = (180° / (pi * 1000) ) * x