Measuring conversions

3ds Max's help quote:
If you do need to change the system unit, change it before you create or import geometry. Do not change the system unit in an existing scene.

Taking into consideration the above quote, what to do when we have to get a value in a different unit? For example, to calculate object speed in kilometers per hour. Max's default unit = 1.0 inches (1 inches = 2.54 centimeters). Would have been nice to have handy in Max similar measure calculator, but for now I use sites like http://www.convert-me.com/en/ , Google also have nice convertor, for example just enter in Google search: "1 km in inches" and will return result: "1 kilometer = 39 370.0787 inches".