Mortgage Calculator
Calculate monthly mortgage payments. Enter home price, down payment, interest rate, and loan term — all in your browser, instant results.
About the Mortgage Calculator
This mortgage calculator runs entirely in your browser. Enter the home price, down payment, interest rate, and loan term to estimate your monthly payment. Nothing is uploaded to a server — all calculations happen instantly with JavaScript on your device.
How the calculation works
The calculator uses the standard amortization formula:
M = P × r × (1 + r)n / ((1 + r)n − 1)
Where P is the loan amount (home price minus down payment), r is the monthly interest rate (annual rate divided by 12, then by 100), and n is the total number of payments (years × 12). If the interest rate is 0%, the monthly payment is simply the loan amount divided by the number of payments.
Frequently asked questions
Does this tool upload my data? No. All calculations happen locally in your browser. Your inputs never leave your device.
Does the calculator include taxes and insurance? No. The result reflects principal and interest only. Add property taxes and homeowner's insurance separately for a true monthly cost.
Can I use a different currency? Yes. The numbers are unit-agnostic — enter values in any currency and the result will be in the same currency.
What is the amortization summary? It shows the breakdown of principal and interest for the first 12 payments, so you can see how much of each early payment goes toward interest versus reducing your loan balance.