House Amortization Calculator

1. Enter the home price and your down payment. The tool subtracts one from the other to get the loan amount.
2. Add the interest rate, loan term and first payment date. Add any extra principal: every month, once a year, or a one-time lump sum.
3. Read the monthly payment and totals, then scroll the schedule. Switch between calendar-year totals and every monthly payment.

What each result tells you:

House amortization is the process of paying off a home loan with equal monthly payments, where each payment covers that month's interest first and the rest reduces the balance. An amortization schedule is the table that shows this split for every payment, along with the balance left afterward.

The schedule helps first-time buyers see where their money goes, owners plan extra payments, and anyone estimate how much interest falls in a given tax year. It is not a full housing budget: property tax, homeowners insurance, mortgage insurance and HOA dues are not part of amortization. For payments that include those costs, use the mortgage affordability calculator.

The monthly payment stays the same, but the interest part shrinks and the principal part grows as the balance falls.

1. Interest for the month = current balance x r.
2. Principal for the month = payment - interest, plus any extra principal you pay.
3. New balance = old balance - principal. The next month starts from the lower balance.
4. The last payment is trimmed so the balance lands at exactly zero.

Because interest is charged on the balance, early payments are mostly interest. Every extra dollar of principal removes future interest on that dollar for the rest of the loan.

A buyer pays 400,000 for a house with 80,000 down, so the loan is 320,000. The rate is 7.03 percent, the Freddie Mac average for a 30-year fixed loan in the week of September 24, 2026, and the first payment is in November 2026.

Meaning: in the first year about 87 percent of the regular payments go to interest. Adding 200 a month saves 119,815.11 in interest and ends the loan 6 years and 10 months early.

Four inputs drive almost everything in an amortization schedule.

Interest Rate

On the 320,000 example, a 30-year loan costs 448,750.92 in interest at 7.03 percent. Rate changes of even a quarter point move the total by tens of thousands over 30 years.

Loan Term

A 15-year loan at the Freddie Mac average of 6.42 percent raises the payment to 2,773.49 but cuts total interest to 179,228.12, less than half the 30-year figure.

Down Payment

A larger down payment lowers the loan, the payment and the interest together, and starts your equity higher. With a small down payment, check whether mortgage insurance applies using the PMI calculator.

Timing of Extra Payments

Extra principal saves the most when paid early. A 20,000 lump sum with payment 12 saves 107,913.80 in interest on the example loan, because it removes 30 years of interest on that amount.

Several calculators on this site look at the same loan from different angles. This one starts from the house price and ties the schedule to real calendar dates.

Before You Buy

Compare down payments and terms to see how each changes the payment, the interest and how fast you build equity.

At Tax Time

The calendar-year view totals the interest paid in each year. IRS Publication 936 explains that your lender reports interest paid on Form 1098, which you can compare with this estimate. Whether you can deduct it depends on your own return.

When You Get Extra Cash

Test a bonus or tax refund as a yearly or one-time payment and see the months and interest it removes before you decide.

1. Treating Principal and Interest as the Whole Payment

Escrow for property tax and insurance can add hundreds a month. Budget for the full amount, not just this figure.

2. Expecting Equity to Build Evenly

Only 3,231.85 of the first year's payments on the example loan reduce the balance. Equity grows slowly at first, then faster.

3. Sending Extra Money Without Instructions

Some servicers hold extra money or apply it to the next payment. Ask that it go to principal, and check your statement.

4. Ignoring Prepayment Terms

Read your note for any prepayment penalty before paying large lump sums.

5. Using This for an Adjustable Rate

The schedule assumes one fixed rate for the whole term. An adjustable-rate loan changes after its fixed period.

The math matches the standard fixed-rate amortization formula, so differences from a lender usually come from rounding or from costs this tool leaves out.

Interest is charged on the balance, and the balance is highest at the start. On a 320,000 loan at 7.03 percent, 22,393.19 of the first 12 payments is interest and only 3,231.85 is principal.

It depends on the rate, balance and how early you start. Enter 100 in the extra monthly field and the tool shows the interest and months saved against the regular schedule.

Monthly extras save slightly more than the same total paid once a year, because each dollar stops earning interest sooner. The difference is usually small next to the total amount you add.

Enter your first payment date and loan details. The Last payment result shows the month and year of the final payment, including the effect of any extra payments.

Yes. Set the home price to your current balance, the down payment to 0, the term to the months left divided by 12, and the first payment date to your next payment.

No. It covers principal and interest only. Add escrow costs from your Loan Estimate or statement to see your full monthly housing payment.

Lenders round each payment and each interest charge to the cent, and some use daily interest. This tool keeps full precision and rounds only for display.

The payment becomes the loan divided by the number of payments, and total interest is 0. The tool handles this case directly.

The Equity after 5 years result adds your down payment to the principal repaid in the first 60 payments. It uses the purchase price and ignores any rise or fall in home value.

No. The calculation runs in your browser and nothing is sent to our servers. Anything you choose to Save stays in this browser only.

• Amortization Schedule (Corporate Finance Institute).
• Primary Mortgage Market Survey: weekly average mortgage rates (Freddie Mac, results as of September 24, 2026).
• Publication 936, Home Mortgage Interest Deduction (Internal Revenue Service, for use in preparing 2025 returns).