How Do I Find What's the Cap Rate for my Area? (NY)

[Roy Assaf]

I have a question for the buy and hold investors,

We decided to start looking for a small multi-family in the NY area (Bronx, Brooklyn, and Westchester) to keep as a rental property. We are studying every day about it and we are working on our budget these days as far as the down payment and a loan. 

My question is how we can find out what's an average cap rate? I know that it changes from an area to an area and probably from a neighborhood to a neighborhood, but is there a formula, resources to look at, etc. 

Any help will be great, thanks!