Is there a way I can specify my loopcuts' distance from the edge using units instead of a [-1,1] value? I'm trying to figure out how I can make a mesh with loop cuts of an exact distance:

 

If I'm making a mesh of something I'm going to subsurf and I want control loops to clean the edges up, I want to have the option of ensuring all the edges will be the same; using a value dependent on the size of the mesh itself for the edge slide doesn't seem conducive to this.
In this case, CtrlB beveling would give you a quick, clean result, with the settings as shown:



Or put the same settings in a Bevel modifier, for instance, by Bevel Weights, for a less destructive method.