Rental Calculator on Primary Residence

[Ciji Masser]

We have tried a few times to run the rental calculator on our primary residence. I can't determine what numbers to place in the purchase and loan area. I know what we owe and the term on the current mortgage, but at this point there's no ‘purchase' involved. I have tried the numbers from our ReFi last October. I have used $0. The ROI seems off in both. Has anyone done this before? If so can your provide the formula or a few pointers.

We have been roof, hvac and windows, water heater was replaced 4 years ago and we would need a new stove and fridge before we could rent it. Two bathrooms have had a full upgrade and one would need some repairs. So we aren’t overly worried about larger repairs in the first 10 years of renting.

Thanks for your help!