Need help analyzing this...Rental ROI

[Mark Baker]

So, here's the numbers on this proposition:

SFH looking to modify into a rental unit targeting local university tenants.

I own property. Property appraised at $300,000.00 $120,000.00  2nd mortgage. Estimate $100,000.00 remodeling/repair/ cost.

So, total debt would be $220,000.00 on refinance. 20 years at 5.25%

Rent $3300/month. 

Property taxes $340/month Insurance $100/month Maintenance $100/month Vacancy 3%(high demand area) 

How would I calculate ROI?

Thanks!