Track every installment, principal share, and interest cost. Model weekly, biweekly, monthly, or quarterly payments. Plan payoff confidently with clear charts, totals, and dates.
Periodic interest rate
r = Annual Rate / Payments Per Year
Automatic regular payment
Payment = P × r / (1 − (1 + r)^−n)
Per-payment breakdown
Interest = Current Balance × r
Principal = Total Payment − Interest
New Balance = Current Balance − Principal
Here, P is the starting debt, r is the rate per payment period, and n is the number of planned payments. Extra payments reduce principal faster, which lowers future interest and can shorten the payoff timeline.
Illustrative sample: $20,000 debt, 8.00% annual interest, 5-year monthly plan, and $50 recurring extra.
| Payment # | Date | Starting Balance | Regular Payment | Extra Payment | Interest | Principal | Ending Balance |
|---|---|---|---|---|---|---|---|
| 1 | Jan 01, 2026 | $20,000.00 | $405.53 | $50.00 | $133.33 | $322.19 | $19,677.81 |
| 2 | Feb 01, 2026 | $19,677.81 | $405.53 | $50.00 | $131.19 | $324.34 | $19,353.46 |
| 3 | Mar 01, 2026 | $19,353.46 | $405.53 | $50.00 | $129.02 | $326.50 | $19,026.96 |
| 4 | Apr 01, 2026 | $19,026.96 | $405.53 | $50.00 | $126.85 | $328.68 | $18,698.28 |
| 5 | May 01, 2026 | $18,698.28 | $405.53 | $50.00 | $124.66 | $330.87 | $18,367.40 |
| 6 | Jun 01, 2026 | $18,367.40 | $405.53 | $50.00 | $122.45 | $333.08 | $18,034.33 |
It shows each payment date, interest charged, principal reduced, extra payments, cumulative interest, total paid, and the exact payoff date.
The calculator computes a standard amortized payment using your debt, interest rate, term, and payment frequency.
Extra payments go toward principal sooner. That lowers the balance faster, reduces later interest charges, and may shorten your repayment schedule.
Yes. After calculation, the summary compares your current setup against the same regular payment without extra payments, when that comparison is valid.
If your total payment does not exceed the interest charged for a period, the balance will not fall. The calculator warns you in that case.
Yes. You can model weekly, biweekly, monthly, and quarterly payments, and the schedule dates adjust to match your selected frequency.
The last payment is adjusted so you do not overpay. It covers only the remaining balance plus the final period’s interest.
Yes. The page includes CSV export, PDF download, and print-to-PDF support for the repayment schedule currently shown.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.