Free Amortization Calculator

You make your payment. Then another payment. Then another one. You check the balance and think: "Wait. Why do I still owe almost the same amount?"

That is amortization. Not because the lender ignored your payment. Not because the entire payment disappeared. It happens because every fixed loan payment is doing two different jobs: paying interest and reducing principal. How much goes to each one changes over time. That is what this calculator is designed to show you.

Start With the Loan Balance

Suppose you borrow $250,000 at 6.5% for 30 years. The modeled principal-and-interest payment is approximately $1,580.17 per month. At first glance, somebody might think: "Okay, I'm paying $1,580 toward my $250,000 balance every month." No. That is not what happens. Part of that $1,580 is the cost of borrowing the money. That part is interest. The rest reduces the balance.

What Happens on the First Payment?

At the beginning of the loan, the balance is still $250,000. At 6.5%, the first month's interest is approximately $1,354.17. Your scheduled payment is $1,580.17. So the amount reducing principal is only about $226.00. After making a $1,580 payment, the balance falls from $250,000 to approximately $249,774. Now it makes sense why the balance can feel like it is moving slowly. Most of that first payment had a different job.

What Happens to the Next Payment?

The next month's interest is calculated on the new, slightly lower balance. Because the balance fell a little, the interest charge also falls a little. That leaves slightly more of the same $1,580 payment available for principal. Then it happens again. And again. Month after month. The interest portion gradually shrinks. The principal portion gradually grows. That repeated process is the amortization schedule.

Why Does the Monthly Payment Stay the Same?

On a standard fixed-rate fully amortizing loan, the scheduled principal-and-interest payment is designed so that the balance reaches approximately $0 after the final scheduled payment. The interest portion is not fixed. The principal portion is not fixed. The total scheduled payment is what normally stays level. That is why the payment-flip visual on this page matters. You can literally watch the same payment change jobs.

What Happens During the First Year?

Using our $250,000, 6.5%, 30-year example, you make approximately $18,962 in scheduled principal-and-interest payments during Year 1. But approximately $16,168 of that is interest. Only about $2,794 reduces principal. At the end of Year 1, the remaining balance is still approximately $247,206. Seeing the numbers laid out like that explains something the monthly-payment number alone never could.

Does That Mean the Loan Is Bad?

No. It means the loan is amortizing according to the mathematical structure you entered. A longer term typically spreads principal across more payments. That can make the required payment lower than a shorter-term loan, but it also means the balance can remain larger for longer. The calculator's job is to show you the tradeoff. It does not decide whether the loan is appropriate for you.

Where Is the Balance After Five Years?

Using the same example: after 5 years, approximately $234,027 remains. After 10 years, approximately $211,940. After 20 years, approximately $139,163. After 25 years, approximately $80,760. The balance starts falling faster later in the schedule because less of each payment is needed for monthly interest.

When Does More of My Payment Start Going to Principal?

That point depends on loan balance, interest rate, and loan term. The calculator calculates the first payment where principal is greater than or equal to interest. That is the principal-interest crossover. Before that point, interest receives the larger part of the payment. After that, principal receives the larger part. The payment itself may not have changed. Its composition did.

An amortization schedule is the complete payment-by-payment map of the loan. For each month you can see: beginning balance, payment, interest, principal, extra principal, and ending balance. That lets you answer questions such as "How much do I owe after five years?", "How much interest have I already paid?", "When does my payment become mostly principal?", and "What happens if I pay extra?" That is much more useful than knowing only the monthly payment.

Monthly Schedule vs Yearly Schedule

A 30-year loan can contain 360 monthly payments. That is a lot of rows. Sometimes you need that detail. Sometimes you just want the bigger picture. That is why this page includes a Monthly Schedule and a Yearly Summary. The yearly table groups 12 payments together so you can see the direction of the loan without scrolling through hundreds of rows.

What Is Total Interest?

Total interest is the sum of all modeled interest charges during the full schedule. For the $250,000 example, total modeled interest is approximately $318,861. That means total principal and interest paid across the original schedule is approximately $568,861. That does not include property taxes, insurance, loan fees, late charges, or other costs. It is principal plus modeled interest only.

Why Can Interest Be Larger Than the Amount Borrowed?

Because the interest cost occurs over time. A loan does not charge interest one time and stop. Interest is repeatedly calculated on the outstanding balance during the schedule. A long loan at a meaningful interest rate can therefore accumulate substantial interest even though the balance is gradually declining.

What Does the Interest Rate Change?

A higher rate increases the amount of interest calculated on the outstanding balance. That usually raises the required payment, increases total interest, or both. A lower rate does the opposite mathematically. The Amortization Calculator lets you change the rate so you can see what the schedule does. It does not predict the rate a lender will offer you.

What Does the Loan Term Change?

Suppose the same amount is borrowed at the same rate. A shorter loan has fewer payments available to repay principal. That usually means higher scheduled monthly payments but less time for interest to accumulate. A longer loan generally produces lower required monthly payments but more payments and potentially more total interest. This is why looking only at the monthly payment can hide part of the borrowing cost.

Now the schedule gets interesting. Suppose our normal payment is $1,580.17. You add $200 toward principal every month. The typical monthly amount becomes approximately $1,780.17. But the important part is that additional $200 is reducing principal. Next month, interest is being calculated on a slightly smaller balance than it would have been otherwise. Then the process repeats. The effect can build over time.

What Can $200 Extra Do in the Example?

Under the modeled $250,000, 6.5%, 30-year scenario, the original loan runs 360 months. Adding $200 of principal every month reduces the modeled payoff period to approximately 265 months. That is around 22 years and 1 month. The modeled timeline is approximately 7 years and 11 months shorter. Total modeled interest falls from approximately $318,861 to approximately $221,243. Difference: roughly $97,618. That does not mean every real loan will produce the same result. Those numbers belong to this specific mathematical example. Change the loan amount, rate, term, or timing of the extra payments and the result changes.

Why Does an Extra Payment Have Such a Large Long-Term Effect?

Because the payment can affect more than one month. If you reduce principal today, future interest is calculated on a lower balance. Then that lower interest charge allows more of later scheduled payments to go toward principal. That can shorten the schedule. The earlier an extra principal payment occurs, the more remaining periods it may influence.

What About One Large Extra Payment?

The calculator models that too. Suppose instead of $200 each month, you make one $10,000 principal payment after Payment 12. Under our example, the modeled payoff period drops from 360 months to approximately 323 months. That is about 37 months sooner. Modeled total interest falls by approximately $49,273. Again, the point is not to tell you to pay $10,000. The point is to show you what the mathematics do if that is a scenario you want to test.

Does Paying Extra Lower My Monthly Payment?

Usually not automatically. If your scheduled payment is $1,580.17 and you send extra principal, the loan balance may fall faster. But the scheduled payment can remain $1,580.17. Some loans may offer a formal recast after a large principal reduction. That is different. This calculator does not automatically recast the loan. It keeps the scheduled payment and lets the lower balance shorten the modeled payoff schedule.

How Do I Make Sure an Extra Payment Goes to Principal?

Check with your lender. This calculator assumes extra amounts are applied directly to principal. A lender may have specific instructions, online principal-only selections, payment-processing rules, minimum amounts, or loan terms that affect how extra money is handled. Do not assume the real loan will process an extra payment exactly the way this calculator models it.

Remaining balance is the principal that has not yet been repaid. It is not necessarily the exact lender payoff quote. Why? A real payoff quote can include interest accrued through the payoff date, fees, other charges, or lender-specific calculations. The schedule's remaining principal balance is still extremely useful, but it is not a substitute for an official payoff statement.

Why Doesn't This Calculator Include Property Taxes or Insurance?

Because those are not part of the loan amortization formula. A mortgage payment can include principal, interest, property taxes, insurance, PMI, HOA, and other housing costs. This page is intentionally focused on principal and interest. Use the Mortgage Calculator if you want the fuller monthly housing-payment picture.

Amortization Calculator vs Loan Calculator

These calculators are related but they answer different questions. The Loan Calculator answers "What is the payment and total borrowing cost?" The Amortization Calculator answers "What happens inside every payment from beginning to end?" If all you need is a quick payment, use the Loan Calculator. If you want the schedule, stay here.

Amortization Calculator vs Payment Calculator

The Payment Calculator is useful when one part of the loan is unknown. For example: "I can afford $500 a month. How much could I borrow?" or "How long will this balance take to pay off?" The Amortization Calculator assumes you already know the loan amount, rate, and term. Then it maps the schedule.

Is a Credit Card Amortized Like This?

Usually not in the same fixed-payment sense. Credit cards are revolving accounts. The balance can change because of new purchases, changing minimum payments, fees, interest, and additional payments. Use the Debt Payoff Calculator or Credit Card Payoff Calculator for revolving debt.

What Is an Interest-Only Loan?

An interest-only period allows payments that may cover only interest for a certain period without fully reducing principal as a standard amortizing schedule would. That is a different loan structure. This calculator does not model interest-only periods.

What Is a Balloon Loan?

A balloon loan can leave a large amount due at the end instead of fully reducing the balance to $0 through equal scheduled payments. That is also different from the fully amortizing structure modeled here.

Does Amortization Mean the Same Thing in Accounting?

Not always. The word amortization is also used in accounting for certain intangible costs or assets. That is not what this page calculates. This CalculateThisWay tool focuses specifically on loan amortization, not accounting or tax amortization.

Do not leave knowing only "My payment is $1,580." Leave knowing: I borrowed $250,000. My modeled payment is approximately $1,580. My first payment contains about $1,354 of interest and only $226 of principal. The balance falls slowly at first because interest is being calculated on a larger balance. Over time, the interest portion shrinks. The principal portion grows.

I can see my remaining balance at any point. I can see every monthly payment. I can switch to an annual summary. I can see exactly when principal becomes the larger part of the payment. I can model recurring extra principal. I can model a one-time principal payment. I can see how the payoff timeline changes. And I can see how much modeled interest changes with it. That is what an Amortization Calculator should actually help you understand.

Sources & Methodology

Important Limitations

This calculator does not automatically model: