This form allows you to compare what would happen if you took one of two choices with some extra cash you have -- prepaying your mortgage each month, or investing it instead. This tries to take into account your tax situation and assumes you always itemize (even late into your mortgage when your interest will be lower.

Change these fields as desired:

How much more you have to spend each month
Current monthly payment (principal & interest only)
Current Annual Loan Interest Rate
Current Loan Balance
Loan Interest Deductibility
Expected Long Term Investment Return (%)
Expected Long Term Tax Rate (%) (Federal+State)
Investment Type