Amortization Schedule Calculator
See how each payment splits between principal and interest until the balance reaches zero.
Published by the Mortgage Guide editorial team. Rate assumptions and content updated October 2026. This page is educational. It is not a loan offer, approval, or personalized financial advice.
How this calculator works
- Each month, interest is the remaining balance times the monthly rate.
- The rest of the scheduled payment reduces principal.
- An extra amount you enter is applied to principal and can shorten the schedule.
- The final contractual payment absorbs leftover cents so the balance ends at zero.
Why the early payments feel like they do so little
On a long fixed-rate loan, the balance starts high, so the interest due each month starts high. The scheduled payment stays level, which means only a smaller slice reduces principal at the beginning.
The yearly chart shows that shift. Later years apply more of the same payment to principal, as long as the rate stays fixed and you do not recast the loan.
Sources
Common questions
Can I download the schedule?
Yes. The CSV is the full monthly schedule, even if the table on screen is showing yearly totals.
Does extra payment reduce interest?
In this model, yes. The result shows interest saved and months saved against the same loan with no extra payment.
Related calculators
- Mortgage Payment Calculator
Estimate a US mortgage payment with principal, interest, taxes, insurance, HOA, and PMI. See the payoff date and amortization schedule.
- Mortgage Payoff Calculator
Compare your current payoff path with an extra monthly payment or a one-time payment. See the new date and interest saved.
- Biweekly Mortgage Payment Calculator
Compare a monthly mortgage with 26 half-payments a year, which equal 13 full monthly payments.
Longer guides on these topics are linked from the guides library.