This window can be accessed through the View menu >Measure Convert.
The Measure/Convert tool allows you to take measurements of distances in your model as well as to convert length/time units. By default, the Measured units will be the model units as defined in the Model Settings window will be selected.
- Click this button to enter "Measure" mode. You can then click anywhere in the 3D view to define your start point, and click again to define the end point. The resulting distance will be displayed to the left.
In the first drop down (shown above as meters), you can select the units to "Measure" with or select a length, time or length per time unit to convert. You may type in your own value to the top field to make a conversion. The bottom field will be the result. The bottom drop down can be changed to convert to different units.