How to determine COC and other useful metrics on rental props

[Charlie Lockwood]

Hi BP Community, 

  New investor/landlord here from Northern Nevada... I bought a house in 2016 (Reno, NV area). My wife and I have lived in it for 5 years. It's appreciated nicely and we've paid down the loan. We recently did a cash-out refi and used these funds to purchase a new home and turn our 2016 property into a rental (close of escrow is end of July)....

Numbers- bought in 2016 for 200k. Appraised in 3/2021 for 350K, loan paid down to 142K. About 200k in equity. 

Cashed out 100k (20% on new place).  New loan around 248k...expected rent around 1650$-1700$,  new mortgage - 1210$ 

My question to ya'll...How do I determine COC on a property I've lived in and now want to make a rental?

I know COC is the amount invested divided by annual cash flow from the property; this is easy to figure out on a property you buy and then turn into a rental right away. I've used the BP calculators but the CoC calculator doesn't seem to fit in my circumstance.

Does this mean I calculate all the money I've put into the property and then figure out my expected annual cash flow (after expenses) to determine COC?

Is there a better metric to use in this instance? 

I know the different in mortgage and expected rent is about 450$ and I know I need to put aside a decent percentage of that for repairs, vacancies, cap ext, etc...

Basically, I'd like some suggestions on how ya'll would keep tabs (numbers, metrics, etc) on this property to ensure that it generates positive cash flow and doesn't turn into a money suck.

Thanks in Advance, 

Charlie