What Numbers Do You Use for Potential Buy and Hold Properties?

[Jon Adamowich]

Hello all, I'm new here to BP and I'm in the beginning stages of purchasing an investment property. I'm currently house-hacking and saving up to purchase a property to rent out; I currently have about $16k in savings and it's growing. I'm curious as to the numbers everyone uses to determine whether or not a potential property will be a good deal for them. Aside from mortgage, taxes, and insurance, what other numbers do you use to calculate expenses? What would you consider to be sufficient cash flow for a single family/duplex/triplex? 

Ideally, I would finance the house with a 15 year mortgage and my down payment would be 20%+ so that I could avoid PMI. I was originally waiting to save up $25k-$35k before really searching for a property, but have seen properties here and there that MIGHT work with the money I have saved up now. I am trying to invest in the Buffalo, NY area.

As someone who is new to real estate, any insight/guidance is very much appreciated. I have a lot to learn!