What Is My Mortgage Amortization Schedule?

Last updated: August 2026

The quick answer: On a $320,000 mortgage at 6.5% for 30 years, the monthly payment is about $2,023 and total interest comes to roughly $408,000. Adding an extra $100 per month saves more interest in year 1 than in year 25. Enter your loan details for your full schedule.

Use the Mortgage Amortization Calculator below — modify the values and click Calculate to see your amortization schedule.

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Please enter a valid loan amount.
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Please enter a valid interest rate (0.1–30%).
years
Please enter the loan term (1–40 years).
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Monthly Payment
$0
Total Interest
$0

Loan Summary

Loan Amount$0
Monthly P&I$0
Total Interest$0
Total of Payments$0
Payoff Date—

With Extra Payments

Monthly Total—
Payoff Date—
Time Saved—
Interest Saved—

Amortization Schedule (Month by Month)

MonthDateInterestPrincipalBalance

How to Read Your Amortization Schedule

  1. Enter Loan Amount, Rate, and Term — for example $320,000 at 6.8% for 30 years.
  2. Add an optional Extra Monthly Payment — even $100/month makes a visible difference in the schedule.
  3. Click "Generate Schedule" to see every month of the loan: interest paid, principal paid, and remaining balance.
  4. Compare the two columns — without vs. with extra payments — to see exactly how much time and interest you save.

Notice how front-loaded the interest is: in the first year of a 30-year loan, roughly 80% of each payment is interest. Only in the final years does most of the payment go to principal. That's the hidden cost of a long loan term — and the reason extra payments in the early years are so powerful.

Why Early Extra Payments Matter Most

Interest is calculated on your remaining balance. Every extra dollar you pay early reduces that balance — and all the interest that would have compounded on it for the remaining 29 years. The same $100 extra payment saves about 4× more interest in year 1 than it would in year 25.

Interest for the month = Balance × (Annual Rate ÷ 12)

Example: $320,000 × 0.005667 = $1,813 interest in month 1
Reduce the balance by $100 → you save 100 × 0.005667 = $0.57 that month, plus the compounding effect for every remaining month of the loan.

Extra Payment Scenarios on a $320,000 Loan at 6.8%

StrategyPayoff TimeTotal InterestInterest Saved
Standard 30-year30 years$431,018—
+$100/month~26 yrs 2 mo$364,318$66,700
+$200/month~23 yrs 3 mo$317,581$113,400
+$500/month~17 yrs 10 mo$232,813$198,200
1 extra payment/yr~23 yrs 11 mo$328,444$102,600

Estimates using standard fixed-rate amortization. Your lender may apply extra payments differently — confirm they go to principal, not toward the next month's payment.

Biweekly vs. Monthly Payments

Switching to biweekly payments (half your payment every two weeks) is a popular strategy: because there are 26 biweekly periods per year, you make the equivalent of 13 full payments per year instead of 12. That extra payment accelerates the payoff by roughly 4–5 years on a 30-year mortgage — without a big lump sum. Just confirm your servicer applies biweekly payments to principal twice a month rather than holding them.

Frequently Asked Questions

What is mortgage amortization?
Mortgage amortization is the process of paying off a loan through fixed monthly payments over a set term. Each payment is split between interest and principal: early payments are mostly interest, and later payments are mostly principal. An amortization schedule is the complete table showing this breakdown for every payment of the loan.
How much does one extra mortgage payment per year save?
Making one extra monthly payment per year on a 30-year mortgage typically pays the loan off 4 to 6 years early and saves tens of thousands of dollars in interest. For example, on a $320,000 loan at 6.8%, one extra payment per year shortens the loan by about 6 years and saves roughly $102,600 in interest.
How much of my mortgage payment goes to interest in the first year?
In the first year of a 30-year mortgage, roughly 70-80% of your payment goes to interest. On a $320,000 loan at 6.8%, you pay about $21,700 in interest during year one and only about $3,300 toward principal. This is why extra payments early in the loan are so powerful — they attack the balance before interest compounds on it.
How do I pay off my mortgage faster?
The most effective strategies are: make one extra payment per year, switch to biweekly payments (26 half-payments = 13 full payments per year), round up your payment to the next $100, or make a lump-sum payment annually. Even $100 extra per month can cut 5-6 years off a 30-year mortgage and save over $50,000 in interest.
Should I use extra payments to invest instead?
The math depends on your mortgage rate versus your expected investment return. If your mortgage rate is 6.8% and you expect investments to return 7%+, investing may win after taxes. But paying down a mortgage is a guaranteed, tax-free return equal to your rate. Many homeowners do a combination: max out retirement contributions, then make extra mortgage payments.

Data sources: Standard fixed-rate mortgage amortization formula, Consumer Financial Protection Bureau (CFPB) mortgage disclosures, Freddie Mac PMMS July 2026. For informational purposes only; extra-payment savings vary by lender policies.

Free Online Calculators

Current Average Mortgage Rates (2026)

Loan TypeAvg. RateTrend
30-yr Fixed6.80%? Stable
20-yr Fixed6.50%? Stable
15-yr Fixed6.10%? Easing
5/1 ARM6.30%? Rising
10-yr Fixed6.05%? Easing

Source: Freddie Mac PMMS, July 2026. For informational purposes only.

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Amortization Quick Facts

  • Roughly 80% of your first-year payments go to interest.
  • One extra payment per year cuts a 30-year loan to ~25 years.
  • Biweekly payments = 13 payments/year = 4–5 years faster payoff.
  • Extra payments save the most when made early in the loan.
  • Confirm extra payments apply to principal, not next month's bill.