Mortgage Calculator

A mortgage is the largest financial commitment most people ever make, and small differences in rate, term, or down payment translate into tens of thousands of dollars over the life of the loan. This mortgage calculator lets you model exactly how those variables interact before signing anything. Enter your home price, down payment, interest rate, and loan term to see your monthly principal and interest payment, the total interest paid over the full loan term, and your complete PITI payment including estimated property tax and homeowner's insurance. The difference between a 15-year and 30-year mortgage illustrates the tradeoffs clearly: the 30-year offers lower monthly payments but often costs twice as much in total interest, while the 15-year builds equity much faster and typically carries a lower rate. Even a half-percentage-point difference in rate — say, 6.5% versus 7.0% — amounts to tens of thousands of dollars on a large mortgage over 30 years. This calculator is equally useful for first-time homebuyers estimating affordability, existing homeowners evaluating a refinance, and real estate investors comparing financing scenarios on rental properties. Run multiple combinations of term, down payment, and rate to find the structure that best fits your financial picture.

The monthly mortgage payment is calculated using the standard fixed-rate amortization formula: M = P × [r(1+r)^n] ÷ [(1+r)^n − 1]. Here P is the loan principal (home price minus down payment), r is the monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (loan term in years × 12). For a 30-year loan at 7.0%, r = 0.07 ÷ 12 = 0.005833 and n = 360. This formula produces a fixed amortizing payment — every monthly payment is the same dollar amount, but its composition changes over time. Early payments are mostly interest; later payments are mostly principal reduction. This gradual shift is called amortization. The total interest paid over the life of the loan is: Total Interest = (M × n) − P. On a 30-year mortgage this figure frequently exceeds the original loan amount, which surprises many borrowers. The calculator adds the optional annual property tax and homeowner's insurance to the monthly P&I to show your full PITI payment — the real number that affects your monthly cash flow. Down payment percentage is also calculated to help borrowers understand when they can avoid Private Mortgage Insurance (PMI), which lenders typically require when the down payment is below 20%.