Based on your home value of $300,000.00, loan amount of $250,000.00, interest rate of 5%, term length of 30 years, 1 points, closing costs of $1,200.00, annual taxes of 1%, annual insurance of 0.5%, annual PMI of 0.4%, federal tax rate of 26%, state tax rate of 5%, and deductions of $3,000.00, your tax savings will be $18,629.49 after the first year and $72,273.23 overall. Your average payment after taxes, during the first year of your mortgage, will be $1,506.56, and $1,616.29 total.

Your total deductions will be $325,639.50, which is calculated by adding your total interest and points to the total property taxes paid. Since these are deductible, they effectively lower your after-tax payment. The amount you will save, then, is $72,273.23 over the life of your loan.