Mortgage Calculator
Calculate your monthly mortgage payment and total interest in seconds.
What is it?
A mortgage calculator is a financial tool that computes your estimated monthly mortgage payment based on the loan amount (principal), annual interest rate, and the term of the loan in years. It uses the standard mortgage amortization formula to show you not just the monthly payment, but also the total amount you will pay over the life of the loan and how much of that total is interest. Understanding your mortgage payment is one of the most important steps in the home-buying process. The monthly payment has two main components: the principal repayment (which reduces what you owe) and the interest charged by the lender (which is the cost of borrowing). Early in a mortgage, most of each payment goes toward interest; as the loan matures, more of each payment goes toward reducing the principal. This is known as amortization. This free online mortgage calculator also lets you factor in additional costs that are often included in a mortgage payment: property taxes, homeowner's insurance, and private mortgage insurance (PMI) if your down payment is less than 20%. You can also model the impact of making extra principal payments to see how much interest you could save and how many months earlier you could pay off the loan.
How to use it
- Enter the home price and your down payment (as a dollar amount or percentage).
- The loan amount calculates automatically as home price minus down payment.
- Enter the annual interest rate offered by your lender.
- Select the loan term — most mortgages are 15 or 30 years.
- Optionally add monthly property tax, insurance and PMI to see your full monthly payment (PITI).
- View the payment breakdown — principal vs. interest — and the total interest paid over the full term.
- Use the "Extra payment" field to model overpayments and see how much time and money you save.
Why use this tool
Buying a home is likely the largest financial decision most people ever make. Before committing to a mortgage, it is essential to understand what your monthly obligation will be, how much of your payment goes to the bank in interest, and what happens to your finances over the full 15 or 30 years of the loan. This calculator gives you all of that in seconds, without needing to consult a loan officer or use a complex spreadsheet. You can quickly compare different scenarios: What if you put 20% down instead of 10%? What if you choose a 15-year term instead of 30? What if interest rates rise by 0.5%? By adjusting the inputs, you instantly see the impact on your monthly payment and total cost. The extra-payment feature is particularly valuable — it shows you in concrete terms how much money you save in interest and how many years you cut from the loan by paying even a modest amount extra each month. Everything runs privately in your browser, with no data collected and no sign-up required.
Frequently asked questions
What does PITI mean?
PITI stands for Principal, Interest, Taxes and Insurance — the four components of a typical monthly mortgage payment. Principal and interest repay the loan itself; taxes are your property taxes paid through an escrow account; insurance covers homeowner's insurance and sometimes PMI.
What is PMI and when do I need it?
Private Mortgage Insurance (PMI) is required by most lenders when your down payment is less than 20% of the home's purchase price. It protects the lender if you default. PMI typically costs 0.5%–1.5% of the loan amount per year and is removed once you reach 20% equity.
What is the difference between a 15-year and a 30-year mortgage?
A 30-year mortgage has lower monthly payments but costs significantly more in total interest over the life of the loan. A 15-year mortgage has higher monthly payments but you pay far less interest overall and build equity faster. Use this calculator to compare both options for your specific numbers.
How do extra payments work?
Making extra payments directly reduces your principal balance. Because interest is calculated on the remaining principal, a lower balance means less interest charged in subsequent months. This creates a compounding savings effect — even small extra monthly payments can save tens of thousands of dollars over the life of a 30-year mortgage.
Does this calculator include property taxes and insurance?
Yes. You can enter your estimated monthly property tax, homeowner's insurance and PMI in the optional fields to see your full estimated monthly payment (PITI). Note that taxes and insurance are estimates — your lender will provide exact figures through an escrow analysis.