Mortgage Calculator

Principal and interest are computed with the standard amortizing-loan formula: M = P · r(1+r)^n / ((1+r)^n − 1), where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments (years × 12). Early payments are mostly interest; later payments are mostly principal. This calculator shows the full split year by year.

A lot, because interest compounds over decades. On a $320,000 30-year loan, moving from 6.0% to 7.0% raises the monthly payment by roughly $210 and adds about $76,000 in total interest. Even a 0.25-point difference is worth thousands, which is why shopping around for lenders matters more than most buyers assume.

Yes, and the effect is larger than people expect because every extra dollar goes straight to principal and removes all the future interest that dollar would have accrued. The calculator shows exactly how many months you cut off and how much interest you save for any extra monthly amount.

A fixed mortgage payment stays the same number every month, but it gets easier to afford each year as inflation lifts wages and prices. So the headline total of payments overstates what the loan truly costs you. This calculator works out what every future payment is worth in today's money to show the real lifetime cost, usually far lower than the headline total when inflation is meaningful. It's one reason a long fixed-rate loan can protect you against inflation.

This calculator models principal and interest (P&I), the part driven by your loan amount, rate, and term. Property tax, homeowners insurance, HOA fees, and mortgage insurance (PMI in the US) are real costs but vary widely by location and lender, so they are not auto-included. Add them separately when budgeting your full monthly housing cost.