Mortgage Calculator
Estimate your monthly mortgage payment, total interest, and full amortization schedule based on home price, down payment, rate, and term.
More options (6)
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.
Worked example
Scenario: A $400,000 home with an $80,000 (20%) down payment, a 6.5% fixed rate and a 30-year term.
- Loan amount: $400,000 − $80,000 = $320,000.
- Monthly rate: 6.5% ÷ 12 = 0.5417%; number of payments: 30 × 12 = 360.
- Payment = 320,000 × 0.005417 ÷ (1 − 1.005417^−360) = $2,022.62.
- Month 1 splits into $1,733.33 interest (320,000 × 0.5417%) and $289.29 principal.
- Total paid: $2,022.62 × 360 is approximately $728,143 before final-payment adjustment; the cent-rounded schedule totals about $728,141, of which $408,141 is interest.
Result: $2,022.62 a month for principal and interest, and about $408,141 in interest over 30 years — more than the amount borrowed.
Mortgage payment per $100,000 borrowed
Because the payment scales in a straight line with the loan amount, the quickest way to sanity-check any quote is the payment per $100,000. Multiply the row for your rate by your loan size in hundreds of thousands: a $320,000 loan at 6.5% is 3.2 × $632.07 = $2,022.62, the same figure as the worked example above.
| Rate | 30-year payment | 30-year total interest | 15-year payment | 15-year total interest |
|---|---|---|---|---|
| 5% | $536.82 | $93,257 | $790.79 | $42,343 |
| 5.5% | $567.79 | $104,403 | $817.08 | $47,075 |
| 6% | $599.55 | $115,838 | $843.86 | $51,894 |
| 6.5% | $632.07 | $127,543 | $871.11 | $56,799 |
| 7% | $665.30 | $139,511 | $898.83 | $61,789 |
| 7.5% | $699.21 | $151,722 | $927.01 | $66,863 |
Two patterns stand out. Each half-point of rate adds roughly $31–$34 a month per $100,000 on a 30-year loan. And a 15-year term costs roughly 44–45% of the 30-year interest at the same rate, for a monthly payment that is about 33–47% higher. In practice the 15-year rate is usually lower too, which widens the gap.
Extra payments: open More options and enter an extra monthly amount. On the worked example, an extra $200 a month pays the loan off in 23 yr 5 mo instead of 30 years and saves $105,428 of interest. Check first that your lender applies extra payments to principal and does not charge a prepayment penalty.
What a mortgage payment estimate may exclude
Principal and interest are only part of many housing payments. Property tax, homeowners insurance, mortgage insurance, association fees, closing costs, and changing escrow amounts may need to be considered separately unless the calculator explicitly includes them.
Tips and common mistakes
- Budget for property tax, homeowners insurance, HOA dues and any PMI on top of this figure; lenders call the full amount PITI.
- Compare terms at their own rates: 15-year loans usually carry a lower rate than 30-year loans, so run each with its real quote.
- A quarter-point matters: at $320,000, moving from 6.5% to 6.25% lowers the payment by roughly $52 a month.
- Use the Amortization Calculator to see how an extra monthly payment shortens the loan.
Assumptions & Limitations
- Uses a fixed interest rate for the entire term — adjustable-rate mortgages will differ after the initial period.
- Optional property tax, homeowners insurance, PMI, and HOA estimates are included in the housing-payment estimate but not in the principal-and-interest amortization schedule.
- 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.
Sources and review
Method: Standard fixed-rate amortization (level-payment annuity) formula with monthly compounding, the method used for installment loans and mortgages.
Sources:
- Consumer Financial Protection Bureau (CFPB) consumer guidance on loan payments, interest and amortization.
- U.S. Truth in Lending Act, Regulation Z (12 CFR Part 1026), which governs how lenders disclose payments and APR.
Last reviewed: October 2026 by Faheem Ali, founder of CalculatorAnything. The method and examples are provided for transparency; results remain estimates and may contain errors.
Results are estimates for planning and comparison, not financial advice or a lender's quote. Rates, fees, tax rules and regulations vary by country and change over time; confirm figures with your lender or a licensed adviser. Spotted an error? Tell us — see our editorial policy for how corrections are handled.