Amortization Calculator
Generate a full loan amortization schedule with monthly or yearly breakdown, extra payments, and cumulative interest
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Amortization Results
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Each row recalculates with your current inputs. Tap a row to apply it.
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Full Amortization Schedule
| Year | Payment | Principal | Interest | Extra | Balance | Cumulative Interest |
|---|
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Amortization Calculator FAQ
What is an amortization schedule?
It is the table showing every periodic payment of a loan, split into interest and principal, with the remaining balance after each payment. Early payments are mostly interest; as the balance falls, more of each payment goes to principal.
How do extra payments change the schedule?
An extra amount paid each month goes straight to principal. That reduces the balance faster, which cuts total interest and shortens the term. The schedule above recalculates instantly, and the summary shows the months and interest saved.
Why is my lender's schedule slightly different?
Lenders may use actual-day interest, irregular first periods, rounding conventions, or escrow rows. This calculator uses the standard 30-day month convention with monthly compounding, which matches most US fixed-rate loan disclosures.
What portion of my first payment is interest?
For any month, interest equals the remaining balance multiplied by the annual rate divided by 12. On a $300,000 loan at 6%, the first month's interest is $1,500 — so on a $1,799 payment only about $299 retires principal at the start.
When do I cross the 50% principal threshold?
Early payments are interest-heavy and the mix shifts slowly. On a 30-year loan at 6%, principal does not exceed interest until roughly year 19 of the schedule; you can see the exact row in the amortization table this calculator produces.
Does refinancing reset amortization?
Yes. A refinance starts a brand-new schedule, which front-loads interest again — that is why refinancing a 30-year loan after 10 years into another 30-year loan can raise lifetime interest even at a lower rate. Compare total interest, not just the monthly payment.
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