How Do I Change the Units Used By Cinema 4D To Something Other Than Centimeters?

Cinema 4D defaults to using Centimeters as the scene units, however, it is possible to use other measurements as well!

Quick Tip: Any field in Cinema 4D can perform math directly within the field. For example, if you need a cube to be exactly 2.75 inches by 3.75 inches by 8 feet (a standard 2x4 construction board size in the United States), you can type these measurements directly into the cube's size fields in its Attributes:

Cinema 4D will then automatically convert these values when you hit Enter or click out of the field:

Cinema 4D fields can do a LOT more math as well, and all fields that have a numerical value can do this. You can even enter equations and it will automatically display the result, but that's another article.

If you'd rather not simply convert the values to the default scene units (i.e., centimeters), you can also change the scene units and the Project Scale.

1. How To Set Scene Units in Preferences:
   The scene units can be set in the Preferences under Units:
   Hotkey to access Preferences is CTRL + E (Windows) or CMD + E (Mac)
   However, this will not change the Project Scale, which will likely still be set to centimeters.
   
   

2. How To Change the Project Scale:
   If you set the units to meters instead of centimeters, the Project Scale will still be in centimeters. If you create a cube, it would default to 2 x 2 x 2 meters because the default size of a cube is 200 project units, which in this case is centimeters; however, it's displayed in meters, and 200 cm is 2 m.

   To display everything in the proper Project Scale as well (i.e., if you want a cube to be 200/200/200 meters instead), you'll need to hit CTRL + D (Windows) or CMD + D (Mac) on your keyboard to bring up the Project Settings, and change the Project Scale to the same Units you set in the Preferences:
   
   
   
   

Once you do this, your scene will be fully converted to your new unit of measurement!