Loan & Amortization Calculator
Estimate fixed loan payments, interest, and faster payoff with extra payments.
Estimate your loan payoff
Estimated payoff
Planned monthly payment
- Scheduled payment
- $483
- Payoff time
- 4 years, 1 month
- Total payments
- $28,206
- Total interest
- $3,206
- Estimated interest saved
- $793
- Estimated time saved
- 11 months
Educational estimate only. Lender schedules and payoff rules can differ.
Your entries and results stay in this browser. This tool does not send, save, or add them to the page address.
How to use the loan calculator
Enter the amount borrowed, annual interest rate, loan term, and any amount you plan to pay above the scheduled payment each month. Use zero for the extra payment to view the original fixed schedule.
The results show the scheduled payment separately from the planned payment with the extra amount. They also estimate the payoff period, total interest, interest saved, and time saved.
How amortization works
A fixed-rate amortizing payment covers the interest charged for the month and reduces the principal. Early in the schedule, a larger share usually goes to interest because the balance is higher. As the balance falls, more of the same scheduled payment reduces principal.
This calculator assumes monthly compounding, equal monthly intervals, and payments made as scheduled. The final payment is limited to the remaining principal and interest rather than charging the full planned amount.
At very high rates combined with very long terms, the scheduled payment barely exceeds the interest charged each month and the balance stops falling in any meaningful way. When that happens the calculator says the loan is not repaid within the term and reports the amount still owed, rather than presenting a payoff that would not occur.
The totals in that situation still cover every payment across the complete term you selected, because a borrower following that schedule would really make them. A loan that only ever covers its interest can therefore show a very large total paid alongside an unchanged balance. Interest saved and time saved are measured against that same complete term, so an extra payment that does clear the balance is credited against what would otherwise have been paid.
Understanding extra-payment estimates
An extra payment can reduce interest only when the lender applies it to principal without a penalty. Loan contracts and servicing rules differ. Confirm how the lender handles extra funds and whether special instructions are required.
The estimate excludes fees, penalties, skipped payments, changing rates, daily-interest differences, and lender-specific rounding. Use the result to compare scenarios, not as a replacement for an official payoff quote.
Frequently asked questions
How is the scheduled monthly loan payment calculated?
The calculator uses the standard fixed-rate amortization formula with a constant monthly interest rate and equal scheduled payments. At a zero percent rate, it divides the principal evenly across the selected months.
How does an extra monthly payment affect the estimate?
The extra amount is applied with each scheduled payment until the balance reaches zero. Because principal falls faster, later interest charges are smaller and the estimated payoff date may arrive sooner.
Why does it show a huge total paid but an unchanged balance?
At very high rates over very long terms the scheduled payment only covers the monthly interest, so it never reduces the principal. The totals still add up every payment across the complete term you selected, because a borrower following that schedule would really make them, but the balance survives it. The calculator says the loan is not repaid within the term and reports the amount still owed.
Does this calculator include fees or prepayment penalties?
No. Origination fees, late fees, optional products, variable rates, payment timing differences, and prepayment penalties are not included. Check the loan agreement before making additional payments.
Is this an amortization schedule from my lender?
No. This is an educational estimate using the values entered. Lenders may use different rounding, daily interest, payment dates, or allocation rules, so their official schedule can differ.