Estimate how long a remaining loan balance will take to repay at your current monthly payment. Add an extra monthly amount or a one-time payment to compare the payoff date and remaining interest. This tool starts from today's remaining balance, not the original borrowed amount. It uses a fixed rate and equal monthly interest periods. A payment that cannot reduce the balance is rejected. The displayed interest saving compares your extra-payment plan with the same balance and rate at the current payment alone.
Worked formula check
The inputs come from CFPB installment-loan sample inputs. This check uses regular monthly periods, excludes the sample's odd first period and other charges, and calculates the outputs with the formula below. It is not a lender offer.
| Input or result | Value |
|---|---|
| Source loan amount | $5,000.00 |
| Source annual interest rate | 12% |
| Source term | 2 years, converted to 24 months |
| Calculated monthly payment | $235.37 |
| Calculated total interest | $648.82 |
| Calculated total payments | $5,648.82 |
Start with the remaining principal
Use the unpaid principal balance from your account statement as the starting amount. Enter the current annual contract interest rate and the amount you intend to pay each month. If the statement's quoted payoff amount includes already accrued interest or charges, it is not necessarily the same as principal. This tool starts a new model at the entered balance and adds a monthly interest period before the first payment. Select the first future payment date to label the schedule. The model does not reconstruct payments you have already made or calculate interest for days before that date.
Test whether the payment makes progress
The tool calculates monthly interest on the remaining balance and applies the payment after that interest. When a recurring payment is too small to cover interest, the balance cannot fall under the regular model. The calculator reports that problem instead of showing a payoff date that the payment cannot achieve. A later one-time payment can change the path, but the full plan still must repay within the calculator's supported payment horizon. If the starting payment is only slightly above monthly interest, inspect the number of payments as well as the monthly amount. You can adjust the recurring payment and calculate again.
Compare recurring and one-time additions
The extra monthly field adds the same amount from the first modeled payment until payoff. The one-time field adds its amount only in the selected payment month. You can use either addition alone or both together. A payment larger than the amount due is capped at the balance plus current interest. The schedule then stops, and later planned additions have no effect. Interest saved is the difference between the modeled baseline interest and your revised plan. If the current payment alone cannot repay the debt within the supported horizon, the baseline is labeled rather than assigning it a saving figure.
Use the date as a planning result
The payoff date is the date of the final monthly row under your selected start date. It is not a lender payoff quote and does not include a per-day interest amount, pending account fees, or a prepayment charge. If you intend to close an account, request the amount and payment instructions from the lender. The CSV can help you review how principal and interest change in this monthly model. For a new loan where you know the term but not the payment, start with the homepage calculator instead. For several debts, the consolidation comparison can show the separate current payments beside a replacement loan.
How it works
r = annual interest rate (%) / 100 / 12
P is the interest-bearing balance, n is the number of monthly payments, r is the monthly rate, and A is the scheduled payment. At a zero interest rate, A = P / n. Each month, interest = opening balance * r; principal = payment - interest; closing balance = opening balance - principal.
This is the regular-payment form of the actuarial relationship in CFPB actuarial formulas, Appendix J. The schedule retains full precision internally and rounds amounts only for display. The model uses a fixed rate and equal monthly periods. It excludes daily accrual, irregular first periods, missed payments, and prepayment charges.
Frequently asked questions
Can I calculate early payoff with extra payments?
Yes. Enter the remaining balance and current payment, then add your monthly extra amount or one-time payment to see the revised monthly payoff path.
Do I enter the original amount or the current balance?
Enter remaining principal. The model calculates future payments from that starting point and does not include past interest.
Why is my monthly payment rejected?
A payment that cannot reduce the balance cannot produce a normal payoff path. Increase it to cover monthly interest and reduce principal, or review the full one-time payment plan.
Is this the same as a lender payoff quote?
No. This is an equal-monthly-period model. A lender quote can use daily accrual, account charges, and payment timing that this calculator does not include.
What happens to an extra payment after payoff?
The model stops once the remaining balance is paid. The final payment is capped at the amount due; later additions are not included.