UNITS IN BLENDER(Blender Version : 2.79b)
Units of measure in Blender are as default set as Blender units. When we open the default screen and then press "N" key to open the properties window where we can see the dimension of the default cube is 2 units along all X,Y and Z axis. These units are defined as Blender units which serves as a general unit of measure to set dimensions of any object or to compare their dimensions.
Measuring units in Blender can also be set as mm(millimetre), cm(centimetre), m(metre) or as inch, feet, yard etc. To set the units with these units, the procedure is as follows:
In the Properties window click on the "scene" BUTTON.(the third button from the left). You will see the drop down panel with heading "Units" and the button marked "None" which would be highlighted with Blue colour. Click on Metric. Now move to 3D window and make sure you have added an object(let us say a Cube). Now hit "N" key to open the panel which would display the location, scale and dimension of the cube. Under Dimension, enter 10cm for x,y, and z dimension. The background grid would change accordingly and the unit as cm will be displayed at the top left corner of the 3D window.
If you select the option "Imperial", then you can set the unit as inches or feet.
