what is a CALM small dog breed?

  Any dog with an owner who rewards calmness and does not nurture overexcitement will be calm. People usually get into trouble when they buy a dog expecting it to naturally behave properly, and don't recognize what they need to do to nurture the proper mindset.
http://www.buzzle.com/articles/calm-dog- ...

Dogs to be considered Small and calm ....

However I dont think you could say each dog in a certain breed will always be like another dog in that same breed
After doing some research on the Yorki or Yorkipoo mix breeds I would get a Yorki or a Yorki mix small breed.
depends how small ..

yorkies are tiny and they're quite calm and capable!

and beagles are slightly bigger but still calm and capable!

they're my favourite small dog breeds.
Shih Tzus.
shih tzu