Trying to rent my home out and buy a rental

[Corey Dussault]

So I used the BP rental calculator to figure out how much I should be charging for rent on my current home. Im looking to rent it out to my mother and I would do a cash out refi to buy a multi family. What my question is how much do people look into the 50% rule and the 2% test as in the videos. Like I said I'm renting it out to my mother and am happy with her paying down the mortgage but I don't want to overcharge her but I do want to cover all repairs and miscellaneous expenses. Does anybody have any advice?