How to Calculate & Formula Details
Mathematical Model Formula
M = P [ i(1 + i)^n ] / [ (1 + i)^n - 1 ] where P is principal, i is monthly interest rate, and n is number of monthly payments.A mortgage calculator helps home buyers estimate their monthly housing expenses. The calculation goes beyond just the loan principal and interest to include other essential factors like property taxes, homeowner's insurance, and private mortgage insurance (PMI).
Components of a Mortgage Payment (PITI)
- Principal: The actual money borrowed to buy the home, which you pay back over the life of the loan.
- Interest: The fee charged by the lender for borrowing the money, determined by your interest rate.
- Taxes: Local real estate or property taxes, which are often held in escrow and paid annually by the bank on your behalf.
- Insurance: Homeowner's hazard insurance and, if your down payment is less than 20%, Private Mortgage Insurance (PMI).
How Interest Rates Impact Payments
Even a 1% difference in your mortgage interest rate can translate into tens of thousands of dollars saved or spent over a 30-year term. Getting pre-approved and maintaining a high credit score is key to securing the lowest possible rate.