Mortgage Calculator
Estimate your monthly mortgage payment, total interest, and full amortization schedule based on home price, down payment, rate, and term.
About the Mortgage Calculator
A mortgage payment is the single biggest line item in most household budgets, and small changes in rate or down payment swing the monthly number by hundreds of dollars. This calculator turns a home price, down payment, interest rate, and loan term into a precise monthly payment, the total interest you will pay over the life of the loan, and a month-by-month amortization schedule so you can see exactly how your balance shrinks over time.
How It Works
The calculator subtracts your down payment from the home price to get the loan principal, then applies the standard fixed-rate amortization formula: it converts your annual rate to a monthly rate, spreads that rate across every month of the term, and solves for the level payment that pays off the loan exactly on schedule. Each month, part of your payment covers interest on the remaining balance and the rest reduces principal — early on interest dominates, and by the final years almost the whole payment goes to principal.
Payment = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan amount, r is the monthly interest rate, and n is the number of monthly payments.
Example
Scenario: A $400,000 home with a $80,000 (20%) down payment, a 6.5% rate, and a 30-year term.
Result: Loan amount of $320,000 produces a monthly payment of about $2,023, with roughly $408,000 in total interest paid over 30 years.
Assumptions & Limitations
- Uses a fixed interest rate for the entire term — adjustable-rate mortgages will differ after the initial period.
- Excludes property tax, homeowners insurance, PMI, and HOA dues, which are commonly bundled into a real monthly mortgage bill.
- Real lenders round payments and may compound slightly differently; use this as a planning estimate, not a binding quote.
- Does not model rate locks, points, or closing costs.