DeluxeCalc

Mortgage Calculator

Estimate your monthly payment and see how every dollar is applied over the life of your loan.

About this calculator

A mortgage is a loan used to buy a home, repaid in equal monthly installments over a fixed term, most often 15 or 30 years. Each payment has two parts: principal, which reduces the amount you still owe, and interest, which is the lender's charge for borrowing. On top of the loan payment, most homeowners also pay property tax, homeowner's insurance, and sometimes homeowners association (HOA) dues. This calculator estimates both the loan payment on its own and the all-in monthly housing cost, and it shows how every payment is split between principal and interest for the full life of a fixed-rate loan.

How to use this calculator

Start with the Home Price and your Down Payment, both entered in dollars; the Down Payment (%) slider sets the same down payment as a share of the price. The calculator subtracts the down payment from the price to get the Loan Amount. Enter the Loan Term in years and the annual Interest Rate your lender quotes for a fixed-rate loan. If your down payment is less than 20% of the price, a PMI Rate (annual) field appears; enter the yearly rate from your lender's quote, or keep the 0.5% default. Then add your estimated monthly Property Tax, monthly Home Insurance, and monthly HOA dues. If your property tax bill is annual, divide it by 12 before entering it. The page starts with example values: a $400,000 home, $80,000 down, a 30-year term at 7.0%, $300 a month in property tax, $120 a month in insurance, and no HOA. Every result updates as you type, and the inputs are saved in the page address so you can bookmark or share a scenario.

The results show five main figures. Monthly P&I is the principal-and-interest payment owed to the lender. Total Monthly adds property tax, insurance, HOA, and any PMI to that payment. Total Interest is the sum of all interest paid until the loan is paid off. Loan Amount is the price minus the down payment. Payoff Time is how long that takes. With less than 20% down, the results also show Monthly PMI, when PMI can be removed on request and when it ends automatically (the number of payments and the time each takes), and Total PMI over the loan. Below the summary, a table compares 15, 20, 25 and 30-year terms at your inputs, a chart shows how much principal and interest you pay each year, and two tables give a yearly summary and a month-by-month amortization schedule with the remaining balance after each payment.

The method is the standard fixed-rate amortization formula. The annual rate is divided by 12 to get a monthly rate, and the term in years is multiplied by 12 to get the number of payments. The monthly payment is the loan amount multiplied by the monthly rate times (1 + monthly rate) raised to the number of payments, divided by (1 + monthly rate) raised to the number of payments minus 1. This produces a payment that stays the same every month and brings the balance to exactly zero at the end of the term. Each month, interest is charged on the balance still owed, and whatever is left of the payment goes to principal. Because the balance is largest at the start, early payments are mostly interest; as the balance falls, more of each payment goes to principal. If you enter a 0% rate, the calculator simply divides the loan amount by the number of payments.

Extra payments and biweekly payments

Under Advanced options you can add an extra amount to principal every month, one-time lump sums in chosen months, or switch to biweekly payments. Biweekly means half the monthly payment every two weeks, with interest charged on the balance each two-week period; 26 half-payments a year add up to 13 monthly payments instead of 12. Every extra dollar lowers the balance that later interest is charged on, so the loan ends early. The final payment is trimmed to whatever is left, and the results show Interest Saved and Time Saved compared with paying only the scheduled amount. On the default $320,000 loan at 7%, an extra $500 a month pays the loan off in 17 years 9 months and saves about $206,900 in interest.

Private mortgage insurance (PMI)

On a conventional loan with less than 20% down, lenders usually require PMI, which protects the lender, not you, if you stop paying. This calculator treats PMI as a yearly percentage of the original loan amount, paid monthly, and adds it to Total Monthly. Typical rates run from about 0.3% to 1.5% a year, depending on your credit score and down payment. Two federal rules (the Homeowners Protection Act) limit how long you pay it. You can ask your servicer in writing to cancel PMI once your balance reaches 80% of the home's original value, if you have a good payment history and the home has not lost value. And your servicer must end it automatically on the date your balance is scheduled to reach 78% of the original value, or at the halfway point of the loan term at the latest. This calculator uses the purchase price as the original value and assumes you ask for cancellation as soon as you can: PMI stops after the first payment that takes your actual balance to 80% of the price. A request can count your actual payments, so extra payments, lump sums and biweekly payments all bring it forward, and the extra payment savings include the PMI you no longer pay. The results also show when PMI would end automatically if you never ask. That date follows your original payment schedule, so extra payments do not move it. Your servicer may still require a good payment history or an appraisal before it agrees to cancel. For example, a $400,000 home with $20,000 down leaves a $380,000 loan. At 0.5% a year, PMI is $158.33 a month on top of about $2,528 in principal and interest. On the regular schedule it can be removed on request after 130 payments (10 years 10 months), costing about $20,583 in total, and it would end automatically after 142 payments (11 years 10 months). With an extra $500 a month it can be removed after 62 payments (5 years 2 months), about $9,817 in total, saving about $10,767 in PMI.

Worked example using the default values

A $400,000 home with $80,000 down leaves a loan of $320,000. At 7.0% over 30 years, the monthly principal-and-interest payment is about $2,129. Adding $300 for property tax and $120 for insurance brings the total monthly cost to about $2,549. In the first month, $1,866.67 of the payment is interest and only $262.30 reduces the balance. Over the first year you pay roughly $22,297 in interest. After 10 years the balance is still about $274,600, and principal does not overtake interest in a single payment until month 242, early in year 21. Over the full 30 years, total interest comes to about $446,428, more than the original loan. Changing only the term to 15 years raises the payment to about $2,876 but cuts total interest to about $197,725, a difference of roughly $248,700.

Interpreting the results

The Total Monthly figure is the number to compare against your budget, because taxes and insurance are real monthly costs even when they are paid through an escrow account. The Total Interest figure is the clearest way to compare loan terms and rates; a difference of half a percentage point can change total interest by tens of thousands of dollars on a large loan. The yearly table is useful for seeing how much equity you will have built at a given point, which matters if you expect to sell or refinance before the loan is paid off.

Practical tips

Try several down payment amounts to see how a smaller loan changes both the payment and total interest. Use the term comparison table to see a 15-year and a 30-year term side by side. Look up actual property tax rates for the area you are considering, since they vary widely between towns and can change your monthly cost more than a small rate difference. Ask an insurance agent for a real quote rather than guessing. Many lenders look at the share of your gross income that goes to housing, so it helps to know your Total Monthly figure before you apply.

Limitations and common mistakes

This calculator models a fixed-rate loan with a constant payment. It does not model adjustable-rate mortgages or interest-only periods. It does not include closing costs, points, or lender fees. PMI is modelled as borrower-paid monthly PMI on a conventional loan; FHA mortgage insurance, VA funding fees, lender-paid PMI and single-premium PMI work differently and are not modelled, and the real end date also depends on staying current on payments and on your servicer's records. Property tax and insurance are treated as fixed monthly amounts, while in reality both tend to rise over time. A common mistake is entering the annual property tax bill in the monthly field, which inflates the total twelvefold. Another is typing a percentage into the Down Payment field, which expects dollars; use the percentage slider instead. Results are estimates for planning and comparison, not a loan offer or financial advice; your lender's Loan Estimate will show the exact figures for your loan.

Frequently Asked Questions

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