The scale starts at 1-to-Donna. If you're rating them at all, they're automatically at the Donna level. Next, you define what class they fall into, like a hurricane or earthquake. 1 is the skinniest Donna and 10 is the hugest, fattest, Donna-est Donna ever.
That Donna is about a Class 5 on the Donna Scale: not enough to immobilize her, but enough to suffocate me if she rolled over in bed.
Lindsay Lohan should stop being an anorexic little whore, it's not like she was ever a Donna or anything. Likewise, the Nichole Richie is the biggest anti-Donna ever.