How much will be the interest rate, and terms of the loan. 

Building a rental portfolio that replaces your income takes years and a lot of effort, this is especially true in our high price high interest rate market.You need to have at least a 10 year vision when buying real estate.

Our occupancy rates have been 65-95% during the peak.

The current tenants are month to month and not interested in buying, and the existing mortgage balance is assumable (3.65%) for qualified buyers.I know it's a great house -- and with the assumable mortgage -- a great buy for someone looking to save with current interest rates sitting as they are. 

Also I've heard of some DSCR loans that are not too far off from conventional rates.  

I wanted to drop this review so that future clients are aware of what they are getting into.

-Ray (see above) is the man and can get you hooked up with great rates and low-fees!

I am unsure how to accurately predict rates and occupancy.

Although 3.1% is a great interest rate I tend to not get too caught up in keeping a property just because the rate is good.

As Vince said it is a quick guideline and won't work in most places with current interest rates and house prices.