What an amortization schedule shows
An amortization schedule is the loan's full diary: every payment, split into the interest it covers and the principal it repays, with the remaining balance after each one. It explains the two facts borrowers find most surprising — why the balance barely moves in the early years, and why extra payments are so powerful (they skip ahead in the schedule, erasing the most interest-heavy months at the end).
How each line is calculated
Repeat monthly: charge interest on what you still owe, subtract it from the fixed payment, apply the rest to the balance. That simple loop, run to zero, generates every schedule on this page. It is also exactly how your lender's system computes your statement — compare a line against a real statement to verify.
Reading the schedule like a lender
- The crossover point: the month where principal first exceeds interest in your payment. On a 30-year loan at 6%, that is around year 19 without extra payments — the schedule shows yours.
- The halfway balance: you do not owe half the loan until well past the halfway date. Equity builds slowly, then fast.
- Extra payments: they delete payments from the end of the schedule — the interest-heavy early payments all still happen, but dozens of later payments vanish entirely.
Amortization beyond mortgages
The same schedule structure governs auto loans, personal loans and business term loans — anything repaid in fixed installments. Interest-only and balloon loans are the exceptions: their schedules show flat or zero principal until a final large payment, which is precisely why generating the schedule before signing matters.
Worked example
A $200,000 loan at 6% for 30 years has a payment of $1,199.10. The very first payment is $1,000.00 interest and only $199.10 principal. Total interest over the schedule is $231,676.38 — more than the amount borrowed — and the balance does not drop below $100,000 until around year 19. Add $200 a month extra and the schedule shortens by 9 years (252 payments instead of 360), saving $79,800.51 of interest.
How to use this calculator
- Enter the loan amount, annual rate and term.
- Optionally add an extra monthly payment.
- Read the payment and totals in the results panel.
- Switch the schedule between annual and monthly views below to inspect individual payments.
- Compare the interest saved stat against the no-extra baseline to judge if extra payments beat investing for you.
Why your lender's schedule may differ by pennies
Lenders round each month's interest to the cent and sometimes adjust the final payment by a few cents so the balance ends at exactly zero. Schedules here use the same cent-level rounding logic in aggregate and may differ from a lender's printout by a few cents over decades — never by dollars.