Amortization Calculator
See exactly how every payment is split between interest and principal, watch your balance fall month by month, and discover how a small extra payment can save you years of interest.
Loan balance over time
Balance falls from $350,000 to $0Payment schedule
| Year | Interest | Principal | Balance |
|---|---|---|---|
| Year 1 | $23,511 | $3,730 | $346,270 |
| Year 2 | $23,251 | $3,990 | $342,280 |
| Year 3 | $22,973 | $4,268 | $338,012 |
| Year 4 | $22,676 | $4,565 | $333,448 |
| Year 5 | $22,358 | $4,883 | $328,565 |
| Year 6 | $22,019 | $5,223 | $323,342 |
| Year 7 | $21,655 | $5,586 | $317,756 |
| Year 8 | $21,266 | $5,975 | $311,781 |
| Year 9 | $20,850 | $6,391 | $305,390 |
| Year 10 | $20,405 | $6,836 | $298,553 |
| Year 11 | $19,929 | $7,312 | $291,241 |
| Year 12 | $19,420 | $7,821 | $283,420 |
| Year 13 | $18,875 | $8,366 | $275,054 |
| Year 14 | $18,293 | $8,948 | $266,105 |
| Year 15 | $17,670 | $9,572 | $256,534 |
| Year 16 | $17,003 | $10,238 | $246,296 |
| Year 17 | $16,290 | $10,951 | $235,345 |
| Year 18 | $15,528 | $11,713 | $223,632 |
| Year 19 | $14,712 | $12,529 | $211,103 |
| Year 20 | $13,840 | $13,401 | $197,702 |
| Year 21 | $12,907 | $14,334 | $183,367 |
| Year 22 | $11,909 | $15,332 | $168,035 |
| Year 23 | $10,841 | $16,400 | $151,635 |
| Year 24 | $9,699 | $17,542 | $134,093 |
| Year 25 | $8,478 | $18,763 | $115,330 |
| Year 26 | $7,171 | $20,070 | $95,260 |
| Year 27 | $5,774 | $21,467 | $73,793 |
| Year 28 | $4,279 | $22,962 | $50,831 |
| Year 29 | $2,681 | $24,561 | $26,271 |
| Year 30 | $970 | $26,271 | $0 |
How amortization works
Amortization is the process of paying off a loan with a fixed series of equal payments. Each payment covers the interest accrued on the outstanding balance plus a portion of principal. Because interest is charged on what you still owe, the early years of a long-term loan are dominated by interest while later payments shift heavily toward principal — even though the dollar amount on your monthly bill never changes.
The math behind the schedule
The standard formula divides the annual rate by 12 to get a monthly periodic rate, then solves for the fixed payment that fully repays the principal over the chosen number of months. From there the schedule is built one row at a time: multiply the current balance by the monthly rate to get interest, subtract that from the payment to get principal applied, then reduce the balance for the next row.
Why extra payments are powerful
An extra payment skips ahead in the schedule. Because every future interest charge is calculated on a lower balance, the savings compound. On a 30-year mortgage, an extra $100 a month can save tens of thousands of dollars and shave several years off the term — without changing your interest rate or refinancing.
Frequently asked questions
What is an amortization schedule?+
An amortization schedule is a complete table of every scheduled mortgage payment, broken down into how much goes toward interest and how much goes toward reducing your loan balance. It shows the balance after every payment until the loan is fully paid off.
Why does so much of my early payment go to interest?+
Interest is charged on the remaining balance each month. Early on the balance is at its highest, so most of your payment covers interest. As the principal drops, the interest portion shrinks and the principal portion grows — even though your total monthly payment stays the same.
How do extra payments change the schedule?+
Every extra dollar you send is applied directly to principal. That permanently reduces the balance interest is charged on, which compounds into months — sometimes years — shaved off the loan and tens of thousands of dollars in saved interest.
Are 15-year and 30-year amortization schedules calculated the same way?+
Yes. The math is identical — only the term length and rate change. A shorter term means a higher monthly payment but dramatically less total interest because the principal is paid down much faster.
Does this calculator handle adjustable-rate mortgages?+
This view assumes a fixed rate. For an adjustable-rate loan, the schedule resets each time the rate changes, so the early years are accurate but later periods would need to be recalculated with the new rate.