Amortization Calculator — Full Schedule & Extra Payments
See every payment split into principal and interest for a mortgage, car loan or personal loan, with a full annual or monthly schedule, the month principal overtakes interest, and how much extra payments save.
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Amortization Schedule
Principal, interest and remaining balance for each period.
| Year | Payment | Principal | Interest | Balance |
|---|
How this calculator works
- Monthly payment: M = P × r ÷ (1 − (1 + r)−n), where P is the loan amount, r the monthly rate (APR ÷ 12) and n the number of payments.
- Each month: interest = balance × r; principal = payment − interest; the balance falls by the principal plus any extra payment.
- Crossover: the first month where the principal part of the payment is larger than the interest part.
Payments cover principal and interest only — property tax, insurance, PMI and HOA fees aren't included (use the Mortgage Calculator for those). Figures are rounded to the cent; your lender's schedule may differ by a few cents.
By Suhaib Hassan · Formula verified 28 Sep 2026 · How CalculatePilot verifies formulas →
A worked example
A $300,000 loan at 6.5% for 30 years: r = 0.065 ÷ 12 = 0.0054167 and n = 360, so the payment is $1,896.20 a month. The first payment is $1,625.00 interest and just $271.20 principal. Over 30 years you'd pay about $382,637 in interest, and principal only overtakes interest at payment 233 — nearly 20 years in. Adding $200 a month pays the loan off 6 years 11 months early and saves about $103,450 in interest.
Why your first payment is mostly interest
Interest is charged on the remaining balance, which is largest at the start. As the balance shrinks, less of each payment goes to interest and more to principal. On a 30-year loan at today's rates, the crossover usually comes after the halfway point, and extra principal payments early on move it much sooner.
How loan term changes payment and total interest
A $300,000 loan at 6.5% APR. A shorter term raises the monthly payment but cuts the interest sharply.
| Term | Monthly payment | Total interest (approx.) | Total paid (approx.) |
|---|---|---|---|
| 15 years | $2,613.32 | $170,398 | $470,398 |
| 20 years | $2,236.72 | $236,813 | $536,813 |
| 30 years | $1,896.20 | $382,633 | $682,633 |
Common amortization mistakes
- Comparing loans by monthly payment only. A longer term lowers the payment but increases total interest, as the table shows.
- Forgetting escrow items. This schedule is principal and interest only. Property tax, insurance, PMI and HOA fees are on top of it.
- Assuming extra payments go to principal. Some servicers apply them to the next payment unless you mark them "principal only", so confirm how yours handles them.
- Refinancing without counting the restart. A new 30-year loan resets the schedule, so early payments are mostly interest again.
Frequently asked questions
Why does most of my early payment go to interest?
Interest is calculated on the remaining loan balance, which is largest at the start of the loan — as the balance shrinks with each payment, less interest accrues and more of the payment goes toward principal.
Does paying extra toward principal reduce total interest?
Yes, significantly — reducing the balance early means less interest accrues on it for the rest of the loan. Enter an extra monthly payment above to see the interest and time saved. Check that your lender applies extra payments to principal and doesn't charge a prepayment penalty.
Is this a full amortization schedule?
Yes. Switch the schedule between annual totals and every monthly payment, each showing principal, interest and the remaining balance, and use Print to save it.
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