Mortgage Calculator
Free to use. Runs in your browser: your files and text are not uploaded.
This tool gives general information only. It is not financial advice.
Enter the home price, down payment, interest rate and term to estimate the monthly payment and see how the loan is paid off year by year.
How to use it
- Type the home price and your down payment.
- Type the yearly interest rate and the loan term in years.
- Add yearly property tax and home insurance if you want them in the monthly figure. Use 0 to leave them out.
The formula
M = P × r ÷ (1 − (1 + r)^−n)
- P = loan amount (home price minus down payment)
- r = monthly rate (yearly rate ÷ 12 ÷ 100)
- n = number of payments (years × 12)
Worked example
A 400,000 home with 80,000 down, at 6.5% for 30 years:
- Loan amount P = 320,000
- r = 6.5 ÷ 12 ÷ 100 = 0.0054167, n = 360
- Principal and interest = 2,022.62 a month
- Tax of 4,800 and insurance of 1,800 a year add 550.00 a month
- Monthly payment = 2,572.62
- Total interest over 30 years = 408,142.36
Why early payments are mostly interest
Interest is charged each month on what you still owe. At the start the balance is large, so most of the payment is interest. In the example, the first year’s payments cover 20,694.69 of interest and repay only 3,576.72 of the loan. In the final year that reverses: 833.39 of interest and 23,438.03 of principal. The table under the results shows every year.
Limits
- The calculation assumes a fixed interest rate for the whole term. Adjustable-rate loans change over time.
- It leaves out private mortgage insurance (often required in the United States when the down payment is under 20%), association fees, and closing costs.
- Property tax and insurance usually rise over the years. The tool keeps them constant.
- Lenders’ figures can differ by a few cents because of rounding, and by more because of fees. Ask a lender for an official loan estimate before deciding.
Frequently asked questions
How is a monthly mortgage payment calculated?
With the standard loan formula: M = P × r ÷ (1 − (1 + r)^−n), where P is the loan amount, r is the monthly interest rate and n is the number of monthly payments.
What is included in the monthly payment shown?
Principal and interest on the loan, plus one twelfth of the yearly property tax and home insurance you enter. Mortgage insurance and homeowners association fees are not included.
How much interest will I pay over the loan?
The line Total interest over the loan shows it. On a 30-year loan the interest is often about as large as the amount borrowed, or larger.