Math Everywhere: How Many People at a Good Party?

Doing some last minute shopping for Sam and ran across Apartment Therapy's post on Party Density.

Seems like they've got it down. I'm having a dinner party on December 25th, I'll have to check the math for the space...

The unanswered question, of course is how many people you should invite to achieve good density of people who actually show up. One strategy of mine is to make my invitations personal if possible rather than sending out a mass evite. People I like will tell me if they are coming or not and I know what's going on that night.

I don't throw barnstormers in my living space anyway. I'd rather throw them at other people's apartments and pay for food or liquor and they provide the space and the cleanup the next day.