Mortgage Calculator

What this calculator does

A mortgage payment is not one number; it is a bundle, and the bundle is where buyers get caught. Principal and interest is only the first line. On top of it sit property tax and home insurance, usually collected monthly into escrow, PMI if the down payment is under 20%, and association dues where they apply. This calculator builds the whole bundle from your figures, for the three structures real mortgages come in: fixed rate, interest-only for a period, and adjustable rate with a fixed start. It adds the planning tools around the payment: extra payments with the savings shown, a balloon date if the loan has one, the date PMI falls away, your equity position after five years, and the payoff date, with the full schedule downloadable. What it will not do is invent program fees or local taxes: FHA, VA and USDA charges follow official rules that change, so anything of that kind goes in only as a figure you enter yourself, and the limitations say so plainly.

How to use it

1. Down payment either way. Type the amount, or type the percentage and the amount is worked out from the price; if both are filled, the percentage wins, and the results line shows the amount and the percentage together so there is never a doubt about which was used.
2. Tax and insurance are annual figures, shown monthly. Enter the yearly amounts (tax also accepts a percentage of the price, which is how many listings quote it) and the results split them into the monthly escrow-style lines, then total them over the life of the payments so the true weight of tax in a high-tax area is visible next to the interest, where it belongs.
3. PMI is charged on the original loan and stops at 80%. Enter the annual PMI rate your lender quotes, as a percentage of the loan. The calculator charges it monthly while the balance is above 80% of the purchase price and stops it the month the balance crosses, which follows the standard cancellation rule for conventional loans, and the results tell you how many months you will pay it and the total. If your program cancels on a different rule, the total here is the benchmark to compare against.
4. Interest-only means exactly that. During the interest-only years the payment covers interest only and the balance does not move, except for any extra payment you enter, which goes straight to principal. When the period ends, the payment is recalculated to clear the remaining balance over the remaining term, and the jump is usually the largest single number on the page. Look at it before choosing the structure, not after.
5. Adjustable rate asks for the adjusted rate directly. There is no index forecast and no cap modelling: you state the rate after the fixed period and the payment is recalculated on the balance and term remaining at that date. Run it twice, once at the rate you hope for and once two points higher, and the pair of answers is the honest picture of an ARM.
6. A balloon date ends the schedule early on purpose. Enter the year the balloon falls due and the results show the lump sum that will be owed on that date, after that month's regular payment. Balloon loans are refinancing plans wearing a payment's clothing, and that lump sum line is the number the plan depends on.

How it is calculated

Principal and interest uses the standard amortization formula, payment = loan x r / (1 - (1 + r) to the power of minus n), with r the monthly rate and n the months, and the schedule is then simulated month by month with interest rounded to cents at each step, exactly like a statement. The final payment settles the exact remaining balance. PMI is the original loan times the annual PMI rate divided by 12, charged in any month whose opening balance exceeds 80% of the price. Interest-only payments are the month's interest on the balance. At an ARM adjustment or at the end of an interest-only period, the payment is recalculated with the same formula on the balance and months remaining. Tax, insurance and HOA are your annual or monthly figures divided or carried as entered; they are costs of the property carried alongside the loan, never part of the balance.

Worked examples

The standard case: price 400,000, down payment 80,000 (20%), loan 320,000 at 6% for 30 years. Principal and interest is 1,918.56 a month. Add property tax of 4,800 a year (400 a month) and insurance of 1,800 a year (150 a month) and the true monthly total is 2,468.56, which is the number a budget has to carry. Total interest over the 30 years is 370,683.35, more than the amount borrowed, and after 5 years the balance is 297,774.07, so equity from payments and down payment is 102,225.93 before any change in the home's value.

Ten percent down, with PMI: the same 400,000 home with 40,000 down borrows 360,000, at the same 6% and 30 years: principal and interest 2,158.38. PMI at 0.5% of the loan per year is 150.00 a month, and it runs for 89 payments, costing 13,350.00 in total, until the balance crosses 320,000. That is the real price of the smaller down payment, next to the 40,000 not spent at purchase, and it is the comparison this page exists to make easy.

Interest-only: a 300,000 loan at 5%, interest-only for 5 years inside a 30 year term. The payment for five years is 1,250.00, and the balance after five years is still 300,000 to the cent. Then the payment resets to 1,753.77 for the remaining 25 years, a jump of over 500 a month arriving on a date known years in advance. Total interest: 301,131.04.

Adjustable: 300,000 at 4% fixed for 5 years, then adjusting to 7% for the remaining 25. The first payment is 1,432.25; at month 61 the payment resets to 1,917.79 on the remaining balance of 271,342.29; total interest 361,272.75. Change the adjusted rate in the inputs and the whole second half of the loan reprices, which is the risk and the tool for sizing it.

Balloon: 200,000 at 6%, payments calculated over 30 years (1,199.10 a month), balloon due after 7 years. After 84 payments the balance, and therefore the balloon, is 179,278.87. Seven years of payments reduced the debt by barely a tenth; the rest was interest. Balloon structures live or die on refinancing that one figure.

Reading your result

Read the bundle, not the headline. Two homes at the same price and rate can differ by hundreds a month once tax, insurance and HOA are in, and over a 30 year schedule the tax total alone rivals the interest. Watch the PMI end date if you are near 20% down: a slightly larger down payment that skips PMI entirely often beats years of PMI plus interest on the extra borrowed. And compare any extra-payment scenario by its two saved lines; on a 30 year mortgage, 200 a month extra on the standard example above clears the loan in 283 payments instead of 360 and saves 92,845.20 of interest, numbers that routinely surprise people who have only ever seen the payment.

Limitations

• Program fees are not built in, deliberately. FHA mortgage insurance, VA funding fees and USDA guarantee fees follow official schedules that change and depend on individual circumstances. Rather than risk stale figures, this calculator takes PMI as a rate you enter from your own quote and leaves program-specific charges to the lender's Loan Estimate, which is legally required to itemise them.
• Tax and insurance are held flat. Both usually rise over a long loan, sometimes steeply. The totals here are the entered figures carried across the payments, a floor rather than a forecast.
• ARM modelling is a scenario, not a prediction. Real adjustments follow an index plus a margin, with caps and floors. Entering an adjusted rate shows the consequence of that rate exactly; it cannot say how likely the rate is.
• Equity ignores the market. The five year equity line is price less balance: your down payment plus principal repaid. What the home could sell for is a different question, addressed by the Home Sale Proceeds Calculator.
• Affordability and rent-versus-buy are their own pages, linked below, because whether you can carry a payment and whether you should are different calculations from what the payment is.

Frequently asked questions

Why is my total monthly payment so much higher than the loan payment?

Because the loan payment is only principal and interest. Tax and insurance are typically collected with it into escrow, PMI rides on top while the balance is high, and HOA dues are billed alongside in many developments. On the standard example, the loan payment is 1,918.56 and the bundle is 2,468.56. Lenders advertise the first number; households live with the second, which is why this page leads with the breakdown.

When does PMI stop, and can I remove it sooner?

On a conventional loan, PMI cancels automatically at 78% of the original price under US rules and can usually be requested off at 80%, which is the threshold this calculator applies to the balance against the purchase price: on the 10% down example that is 89 monthly charges. Paying the balance down faster with extras brings the date forward, and the extras comparison on this page reflects PMI ending sooner as part of the saving. Appreciation-based removal, where a new valuation shows 20% equity, is a lender process no calculator can date for you.

Is a 15 year mortgage worth it next to a 30 year?

Run both. The 15 year payment is much higher but the interest total collapses, because the balance falls fast and interest is charged on the balance. Many households take the 30 year and pay it like a 15 using the extra payment field, which keeps the contractual payment low while aiming at the same payoff; the extras lines show exactly how close that gets, though it lacks the 15 year's lower rate, which is the part only a lender quote can give you.

What does interest-only actually cost?

Time. In the example, five interest-only years cost 75,000 of interest and reduce the balance by nothing, then the payment jumps by over 500 a month for the remaining 25 years. Interest-only has legitimate uses, bridging and variable income among them, but the cost line to read is total interest next to a fixed rate run of the same loan, and this page makes that a two-minute comparison.

Related calculators

• All Money and Finance Calculators
• Mortgage Affordability Calculator
• Closing Cost Calculator
• Home Sale Proceeds Calculator
• Rent vs Buy Calculator

Method: standard amortization with interest rounded to cents monthly and the final payment settling the exact balance; PMI charged on the original loan while the opening balance exceeds 80% of the price; interest-only and ARM payments recalculated on the remaining balance and term at each change; tax, insurance and HOA carried as entered, outside the loan balance. Last reviewed: 13 October 2026.