CR of NPCs with Class Levels

[Grocolo]

I am planning to design an NPC with Druid class levels. I want to use one of the Core Rulebook races, but I can't find where to calculate the CR. I seem to recall something like class level minus one?

[Mahorfeus]

If the NPC has player class levels, then its CR is equal to its total character level. If an NPC has NPC class levels, you subtract 2 from the CR (except in special cases like the kobold, with which you subtract 3). That's the way I run it anyway.

Edit For Unnecessary Example: So if your Druid is level 5, it would be CR 5; on the other hand, a level 5 Adept would be CR 3.