JavaScript must be enabled in order to use this site.Please enable JavaScript in your browser and refresh the page. Changing the units You can change either the unit system or individual units. Choose Criteria > Units. Do one of the following: Select each unit by accessing the appropriate drop down box. or Select a unit system by clicking on US, SI, or MKS at the top of the window. Note: There is often a long list of choices for the units. Scroll down the drop down menu to view the options. Units Window Parent topic: Selecting units