I agree with sdrealtor. The tax break should be looked as a bonus of sorts. If you can’t afford the place without the tax adjustment, you probably can’t really afford it.
That being said. I found an excel spreadsheet that computes the deduction for you based on your inputs. I modified it to estimate your effective payment after property tax and mortgage interest deduction based on your tax rate. I even make an attempt at guestimating PMI.
It has proven to be pretty accurate so far +/- a percent or two.
I think my google query was something like “mortgage calculator excel”.
I think the web site was vertex something or other.
I hope that helps.
Or, PM me an email address and I’ll send you what I have.
