A mortgage payment is the monthly amount you pay to your lender to repay a home loan. Most people think of it as a single number, but it actually consists of up to four components, commonly abbreviated as PITI: principal, interest, taxes, and insurance.

Principal is the portion that reduces your loan balance. Interest is the cost of borrowing, calculated as a percentage of the remaining balance. Early in a loan, most of your payment goes toward interest. Over time, the balance shifts so that more goes toward principal — this is how amortization works.

Property taxes are assessed by your local government, typically as a percentage of your home's assessed value. Rates vary widely by state and county — from under 0.3% in Hawaii to over 2% in New Jersey. Homeowners insurance protects against damage and liability. Lenders require it as a condition of the loan.

Amortization is the process of spreading a loan into a series of fixed payments over time. With a fixed-rate mortgage, your monthly principal-and-interest payment stays the same for the life of the loan, but the split between principal and interest changes every month.

In the first month of a 30-year, $400,000 loan at 7%, roughly $2,333 goes to interest and only $329 goes to principal. By month 180 (halfway through), the split is roughly $1,566 interest and $1,096 principal. By the final year, almost the entire payment reduces the balance. This front-loading of interest is why making extra payments early in a loan has an outsized impact on total interest paid.

The amortization schedule in this calculator shows every month of your loan, so you can see exactly when the crossover happens and how much equity you build at each stage.

Private Mortgage Insurance (PMI) is required by most lenders when your down payment is less than 20% of the purchase price. PMI protects the lender — not you — if you default on the loan. It typically costs between 0.5% and 1.5% of the original loan amount per year, added to your monthly payment.

PMI is not permanent. Once your loan balance drops below 80% of the home's original value (or current appraised value in some cases), you can request cancellation. Under federal law, your lender must automatically cancel PMI when your balance reaches 78% of the original value. This calculator models PMI as dropping off at the 80% threshold so you can see the month your payment decreases.

Start with the purchase price and down payment to see your base loan amount. The interest rate defaults to the current national average from Freddie Mac's weekly survey, but you should adjust it to match a rate quote from your lender. Choose between a 15-year and 30-year term — shorter terms have higher monthly payments but dramatically lower total interest.

Property tax rates default to your state's median effective rate based on your location, but you can override this with your actual rate. Insurance defaults to a national average estimate. All inputs update the URL instantly, so you can bookmark or share any scenario.