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Loan Amortization Schedule

Full Payoff Schedule with Extra Payments

Last reviewed: January 2026

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What Is a Loan Amortization Schedule?

A loan amortization schedule breaks down every payment over the life of a loan into principal and interest components. It shows how each payment reduces your balance and how much total interest you will pay, helping you understand the true cost of borrowing and plan extra payments.

Reading an Amortization Schedule

In a standard amortization schedule, early payments are mostly interest — on a 30-year mortgage, the first payment might be 80%+ interest and only 20% principal. This reverses over time. Extra payments go entirely to principal, dramatically reducing total interest. An extra $100/month on a $250,000 mortgage at 7% saves over $40,000 in interest and cuts 5+ years off the loan. Even irregular lump-sum extra payments (tax refunds, bonuses) have significant impact when made early in the loan term.

Amortization: Interest vs Principal Over Time ($250K, 6.5%, 30yr)

YearMonthly PaymentInterest PortionPrincipal PortionRemaining Balance
Year 1$1,580$1,348$232$247,216
Year 5$1,580$1,270$310$233,065
Year 10$1,580$1,143$437$213,456
Year 20$1,580$780$800$155,600
Year 30$1,580$17$1,563$0

What Is an Amortization Schedule?

An amortization schedule is a complete payment-by-payment breakdown showing exactly how each loan payment divides between principal and interest over the entire loan term. In the early years of a mortgage, the majority of each payment goes toward interest — on a 30-year, $300,000 mortgage at 6.5%, the first monthly payment of $1,896 allocates approximately $1,625 to interest and only $271 to principal. By year 15, the split is roughly equal ($948 each). In the final year, nearly the entire payment goes to principal. This front-loading of interest is why extra payments in the early years are so valuable — every additional dollar of principal in year 1 saves $2.86 in total interest over the loan's life at 6.5%.

30-Year vs. 15-Year Amortization Comparison

$300,000 at 6.5%30-Year15-YearDifference
Monthly payment$1,896$2,613+$717
Total interest paid$382,633$170,420−$212,213 saved
Total cost$682,633$470,420−$212,213 saved
Equity at year 5$22,880$81,350$58,470 more equity

How Extra Payments Reshape the Schedule

Adding extra principal payments recalculates the remaining amortization, reducing both the remaining term and total interest paid. Adding $200/month to the payment on a $300,000, 30-year mortgage at 6.5% saves approximately $93,000 in interest and pays off the loan 6.5 years early. The effect is most dramatic when extra payments begin early in the loan term. A one-time $5,000 extra payment in year 1 saves approximately $14,300 in total interest, while the same $5,000 payment in year 20 saves only $3,200. This decreasing leverage is why financial advisors emphasize extra payments early in the loan's life. Model your extra payment scenarios with our Extra Payment Calculator.

Biweekly Payment Strategy

Switching from monthly to biweekly payments (paying half the monthly amount every two weeks) results in 26 half-payments per year — equivalent to 13 full monthly payments instead of 12. This single extra payment annually can shave 4–5 years off a 30-year mortgage and save tens of thousands in interest. On the $300,000 example at 6.5%, biweekly payments reduce the loan term to approximately 25 years and save roughly $68,000 in interest. Some lenders offer formal biweekly programs (sometimes with fees), but you can achieve the same effect by simply adding 1/12 of your monthly payment to each regular payment. Track your mortgage progress with our Mortgage Payment Calculator.

Negative Amortization Warning

Some loan structures — particularly certain adjustable-rate mortgages, payment-option ARMs, and some student loan income-driven repayment plans — can result in negative amortization, where your payment does not cover the full interest charge. The unpaid interest adds to your principal balance, meaning you owe more over time despite making regular payments. A $200,000 loan with $1,000/month payments where $1,200/month of interest accrues grows to $202,400 after one year of negative amortization. Always verify that your payment exceeds the monthly interest charge. If you are on an income-driven student loan plan where payments do not cover interest, understand that forgiveness after 20–25 years may result in a large taxable forgiveness amount.

Reading Your Amortization Schedule

Your amortization schedule reveals several valuable insights beyond payment allocation. The cumulative interest column shows the total interest paid to date — helping you calculate the real cost of your loan at any point. The remaining balance column indicates your equity position when combined with your home's current value. The principal portion trending line shows your equity acceleration — once the principal portion exceeds the interest portion (typically around year 20 of a 30-year loan), your equity builds rapidly. Use this visibility to make informed decisions about refinancing, extra payments, and home equity borrowing. Compare refinancing options with our Refinance Calculator and understand your full equity picture with our Home Affordability Calculator.

ARM Loans and Variable Amortization

Adjustable-rate mortgages (ARMs) create amortization schedules that change when the rate adjusts. A 5/1 ARM starts with a fixed rate for 5 years, then adjusts annually based on an index (typically SOFR) plus a margin. If your initial rate is 5.5% and the rate adjusts to 7.5% in year 6, your monthly payment on a remaining $280,000 balance jumps from approximately $1,703 to $1,956 — a $253/month increase. Rate caps limit how much the rate can change per adjustment (typically 2% per year) and over the loan's life (typically 5–6% above the initial rate). Understanding the amortization impact of rate changes helps you plan for potential payment increases and decide whether to refinance before adjustments begin.

Amortization and Home Equity Growth

Your amortization schedule, combined with home price appreciation, determines your equity-building trajectory. On a $400,000 home with a $350,000 mortgage at 6.5% for 30 years, you build approximately $16,000 in equity through principal payments in the first 3 years. If the home appreciates at 3% annually during the same period, appreciation adds another $37,000 in equity — for a total of $53,000 from the initial $50,000 down payment. Understanding these dual equity sources helps time decisions about HELOCs, PMI removal, and refinancing. Track your equity position with our HELOC Calculator and model your total housing cost with our Rent vs Buy Calculator.

Why do I pay more interest at the beginning of a loan?
Each payment's interest portion is calculated on the remaining balance. Early in the loan, the balance is highest, so most of your payment goes to interest. On a $300,000 mortgage at 7%, your first monthly payment is $1,996 — but $1,750 goes to interest and only $246 to principal. By year 15, it reverses: $988 to principal and $1,008 to interest.
What is negative amortization?
It occurs when your monthly payment is less than the interest owed, causing the loan balance to grow instead of shrink. Some adjustable-rate mortgages and income-driven student loan repayment plans allow this. You end up owing more than you originally borrowed. Avoid negative amortization unless you have a specific strategy and repayment plan.
Why do early loan payments go mostly toward interest?
In an amortizing loan, interest is calculated on the remaining principal balance each period. Since the balance is highest at the beginning, the interest charge is largest in early payments. As you pay down principal, less interest accrues, so more of each fixed payment goes toward principal. On a 30-year $300,000 mortgage at 7%, the first payment applies only $237 to principal ($1,758 to interest), but payment 180 (halfway) applies $726 to principal. This front-loading of interest is why extra payments in the early years have such a dramatic effect on total interest and loan duration.
Why do I pay so much interest at the beginning of a loan?
Interest is calculated on the outstanding balance each month. At the start, the balance is highest, so the interest charge is largest. As you pay down principal, each subsequent interest charge shrinks, leaving more of the fixed payment for principal reduction. This creates an accelerating payoff effect — the same $1,580 payment reduces principal by $232 in year 1 but $1,563 in year 30.
How does making extra payments affect amortization?
Extra payments go directly to principal reduction, which lowers the balance that accrues interest in all future months. This creates a compounding savings effect. One extra monthly payment per year on a $250,000 mortgage at 6.5% saves approximately $60,000-$80,000 in total interest and shortens the loan by 4-5 years. The savings are largest when extra payments start early in the loan term.

See also: Mortgage Calculator · Extra Payment Calculator · Refinance Break-Even Calculator

How to Use This Calculator

  1. Enter the loan amount and interest rate — Input the total principal borrowed and the annual interest rate. The calculator converts the annual rate to a monthly rate for payment computation.
  2. Set the loan term — Enter the repayment period in months or years. Common terms are 15 or 30 years for mortgages, 36–72 months for auto loans, and 10–25 years for student loans.
  3. Add extra payments if applicable — Enter any additional monthly payment amount above the minimum. Even small extra payments dramatically reduce total interest and payoff time by attacking the principal directly.
  4. Review the month-by-month schedule — The amortization table shows each payment split into principal and interest, running balance, and cumulative interest paid. Early payments are mostly interest; later payments are mostly principal.

Tips and Best Practices

In year one of a 30-year mortgage, roughly 70–80% of each payment goes to interest. On a $300,000 loan at 7%, your first payment of $1,996 puts $1,750 toward interest and only $246 toward principal. This ratio gradually flips — by year 25, most of the payment goes to principal. Understanding this reveals why early extra payments are so powerful.

An extra $100/month on a 30-year mortgage can save 5+ years and $50,000+ in interest. Extra payments go entirely to principal, reducing the balance that accrues interest for the remaining term. The earlier you start making extra payments, the greater the compounding savings. Our Mortgage Calculator models extra payment scenarios.

Biweekly payments are a painless hack. Paying half your monthly payment every two weeks results in 26 half-payments = 13 full payments per year instead of 12. That one extra payment per year can cut a 30-year mortgage to ~25 years with no change in lifestyle spending. Verify your lender applies biweekly payments correctly — some hold them until month-end, negating the benefit.

Refinancing restarts the amortization clock — check the break-even. If you're 10 years into a 30-year mortgage and refinance into a new 30-year, you extend your payoff by a decade. Consider refinancing into a 20-year term to maintain your timeline, or refinance into 30 but continue making your current (higher) payment amount. Use our Refinance Calculator for break-even analysis.

See also: Mortgage Calculator · Refinance Calculator · Interest Rate Calculator · Simple Interest Calculator

📚 Sources & References
  1. [1] CFPB. Amortization Explained. ConsumerFinance.gov
  2. [2] Freddie Mac. Understanding Your Mortgage. FreddieMac.com
  3. [3] Federal Reserve. Mortgage Mathematics. FederalReserve.gov
  4. [4] Fannie Mae. Loan Terms Glossary. FannieMae.com
Editorial Standards — Every calculator is built from peer-reviewed formulas and official data sources, editorially reviewed for accuracy, and updated regularly. Read our full methodology · About the author