Mortgage payment calculator
Estimate a mortgage payment and the full payoff path.
- Formula and assumptions shown
- Table and CSV export
- Runs in your browser
How it works
The core payment amortizes the entered principal over the selected term. Optional ownership costs are shown separately so you can see which part comes from principal and interest versus amounts you supplied.
Payment = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where r is the periodic rate and n is the number of payments.
This is a planning estimate for a fixed-rate loan. It does not fetch mortgage rates or calculate local taxes, insurance premiums, or lender eligibility.
Assumptions
- The entered annual rate is fixed and divided by 12 for monthly payments.
- Principal and interest payments fully amortize the loan over the entered term; displayed amounts are rounded only for reading.
- Property tax and insurance are entered as annual amounts and divided by 12; HOA and PMI are entered as monthly amounts.
- Origination fees, extra principal payments, escrow timing, and adjustable-rate changes are excluded.
Worked example
$240,000 at 6% for 30 years
The principal-and-interest payment is about $1,438.92 per month. Adding $3,600 annual property tax and $1,800 annual insurance ($450 per month together) gives an estimated total of $1,888.92; HOA and PMI are $0 in this example.
Step by step
- Monthly rate and number of payments. The 6% annual rate is divided by 12: 6% ÷ 12 = 0.5% a month (0.005). A 30-year term has 30 × 12 = 360 monthly payments.
- Growth factor. (1 + 0.005)^360 = 6.022575. This is how far one dollar of balance would grow over 360 months if nothing were paid.
- Principal and interest. $240,000 × 0.005 × 6.022575 ÷ (6.022575 − 1) = $1,438.92 a month. In month one, $240,000 × 0.005 = $1,200.00 of that is interest and $238.92 reduces the balance.
- Other ownership costs. Property tax of $3,600 ÷ 12 = $300.00 and insurance of $1,800 ÷ 12 = $150.00 add $450.00 a month. HOA dues and PMI are $0 in this example.
- Estimated monthly payment. $1,438.92 + $450.00 = $1,888.92. Over 360 payments, principal and interest add up to $518,011.65, of which $278,011.65 is interest.
How to read your result
The headline, Estimated monthly payment, is principal and interest plus the monthly share of the property tax, insurance, HOA dues, and PMI you entered. Principal and interest is the only part set by the loan itself, and on a fixed-rate loan it stays the same for the whole term. Other monthly ownership costs is simply your entries converted to a monthly figure; the calculator does not look them up. When tax and insurance are paid through an escrow account, the servicer resets that portion as bills change, so it can move from year to year even though principal and interest do not.
Total interest is what the scheduled payments cost beyond the amount borrowed if every payment is made on time and nothing extra is paid. It excludes taxes, insurance, closing costs, and points. The payment breakdown splits the monthly total into its parts, and the balance chart and schedule show how slowly an amortizing loan shrinks at first: in the $240,000 example, the first 60 payments include $69,665.73 of interest and only $16,669.54 of principal, and the balance does not fall below half the original amount until month 252.
The estimate leaves out closing costs, discount points, rate changes on an adjustable-rate loan, and extra principal payments. It also says nothing about whether a lender would approve the loan; the affordability and debt-to-income calculators cover that side.
What changes the result most
- Interest rate
- At 7% instead of 6%, principal and interest on the $240,000 example rises from $1,438.92 to $1,596.73, which is $157.80 more a month, and total interest grows from $278,011.65 to $334,821.36.
- Loan term
- A 15-year term raises principal and interest to $2,025.26 a month but cuts total interest to $124,546.15, which is $153,465.50 less than the 30-year loan.
- Loan amount
- Principal and interest scale in proportion to the amount borrowed. At 6% for 30 years, each extra $10,000 adds $59.96 a month, so borrowing $260,000 instead of $240,000 gives $1,558.83.
- Taxes, insurance, HOA, and PMI
- These add dollar for dollar and do not depend on the rate. Every $1,200 of annual property tax adds $100 a month, so in high-tax areas they can move the total as much as a rate change.
Questions
Why is my total housing payment higher?
Property taxes, insurance, HOA dues, and mortgage insurance can sit outside principal and interest. Enter those amounts separately when you have them.
Does this use today's mortgage rates?
No. Enter the rate you want to test. The site has no live financial feed.
Can I model extra principal?
Use the extra-payments calculator for the recurring-extra scenario, then compare the two schedules.
How is a mortgage payment calculated?
The principal-and-interest part uses the standard amortization formula: payment = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the loan amount, r is the annual rate divided by 12, and n is the number of monthly payments. That fixed payment brings the balance to exactly zero after the last payment. Monthly property tax, homeowners insurance, HOA dues, and mortgage insurance are then added to get the full housing payment, which is what the headline shows.
How is the interest on a mortgage calculated each month?
Each month the interest is the outstanding balance times the monthly rate. In the $240,000 example at 6%, month one’s interest is $240,000 × 0.005 = $1,200.00. Because the payment is fixed, the interest share falls as the balance falls, and more of each payment goes to principal. A servicer’s statement can differ by a few cents because of rounding.
How much is PMI per month?
It depends on the loan amount, the down payment, the credit score, and the insurer, so there is no single figure. Lenders quote it as an annual percentage of the loan or as a monthly dollar amount on the Loan Estimate; enter that monthly amount here. On conventional loans, federal law generally lets a borrower ask to cancel PMI once the balance is scheduled to reach 80% of the home’s original value and ends it automatically at 78% if payments are current. FHA mortgage insurance follows separate rules.
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Sources
These references explain the concepts behind the calculation. They do not endorse this site. Estimates leave out any cost or condition you did not enter.